Warming ends when emissions stop

Mann's article shows that temperatures will most likely quickly stop rising if we stop emitting CO2 and methane.

[See original chart here]

From Michael E Mann

A recent article in The Hill insisted that “scientists failed for decades to communicate” (1) the threat of climate change. The scientific paper on which the article was reporting did not really say that—it was instead providing a more nuanced discussion of sea level rise “tail risk”. But the irony here is that the opposite of what was asserted by the news article is arguably true. If anything, we scientists have failed to communicate the prospects for averting catastrophic warming. 

In the days when I was working on my PhD, in the early 1990s, we were taught that the warming of the planet would persist for decades even if we suddenly stopped burning fossil fuels and emitting carbon into the atmosphere. This is due to what is known as “thermal inertia”—the slow, sluggish response of the oceans. Climate models showed that surface warming would continue for 30 years or more, as the oceans slowly continue to warm, even after carbon pollution ceases. This so-called “committed warming” would seem to render our efforts to avert disaster somewhat futile. Even if we turned off the metaphorical carbon faucet, the water level of warming would continue to rise. Extending the metaphor, that water would soon spill from our kitchen sink onto the kitchen floor. With apologies to Greta Thunberg, rather than burning, our house would instead be flooding.

But that picture is fundamentally incomplete—there is a “drain” too in the form of the ocean carbon cycle. That drain causes the water level, i.e., the planetary temperature, to stabilize. Through a somewhat fortuitous coincidence of nature, there are offsetting tendencies in ocean physics and ocean chemistry. The positive “thermal inertia” (the physics) is almost perfectly offset by a negative “carbon cycle inertia” (the chemistry). To be more specific, the rate at which the ocean surface tends to continue to warm up due to the carbon already emitted is nearly identical to the rate at which the oceans absorb and bury atmospheric carbon dioxide (CO2), lowering the atmospheric greenhouse effect and cooling the lower atmosphere and surface. The two effects essentially cancel each other out. And so, instead, we get an essentially flat temperature curve—the stable metaphorical water level—when human carbon emissions approach zero.

In the old days, climate modelers would simply set the atmospheric CO2 constant to represent a scenario in which human carbon emissions cease. However, this amounted to an erroneous implicit assumption of zero carbon cycle inertia. In the newer, more realistic modeling framework, based on more comprehensive Earth system models, the oceans as well as the terrestrial biosphere are allowed to play an interactive role in the behavior of the system, which includes the key role of actively drawing down carbon from the atmosphere.

While this new more realistic framework emerged more than a decade ago (2), only far more recently has it truly penetrated public climate discourse. Arguably, both scientists and journalists are at fault (3) for the continued notion that we are due decades of additional warming even after we cease fossil fuel burning and other activities generating carbon pollution. We now know this is not true.

This is hardly a minor technical matter. It fundamentally changes our sense of agency in averting disaster. It means our efforts to reduce carbon emissions have a direct and immediate impact. It is the reason we can meaningfully define a “carbon budget”—there is a fixed amount of fossil fuel we can afford to burn and stay below critical planetary temperature levels such as 1.5°C or 2.0°C. We can estimate that budget and work toward policies that can keep us collectively within it, at least in principle.

Old habits die hard, and some scientists have remained skeptical of this revised understanding. Indeed, I myself took several years to accept the paradigm-shifting implications of this finding. But this finding appears quite robust, having been affirmed by a solid body of work over the past decade. The current state of the science is adroitly summarized in a comprehensive new review “The Zero Emissions Commitment and climate stabilization” by a team of nearly two dozen experts on this research topic in the current Frontiers in Science Lead Article by Palazzo Corner et al. (4).

Palazzo Corner et al. focus on the “Zero Emissions Commitment” or “ZEC”, which is defined as how much warming (if any) we can expect upon reaching zero carbon emissions. Technically, that is zero “net emissions”, as the possibility exists— at least theoretically—for artificial drawdown of atmospheric carbon, i.e., so-called “negative emissions”. Yet there is no evidence at present that such technology could be deployed at scale let alone in the rapid timeframe now necessary. To the extent that the ostensible promise of negative emissions technology may be little more than a techno-optimistic mirage, my preference is to omit the “net” prefix. What is truly required is a rapid phaseout of anthropogenic activities that produce carbon pollution.

Palazzo Corner et al. show that, on average, the various models used in the recent “ZECMIP” intercomparison study indicate a ZEC close to zero, at least on a 50-year timescale (greater uncertainties apply for longer timescales due to uncertainties in the longer-term behavior of, e.g., the global carbon cycle and for larger amounts of cumulative carbon emissions). For at least 1000 gigatons (trillion tons) of emitted carbon (“GtC”) (thus far, for comparison, we have burned about 680 GtC, so it is plausible we can remain below that limit), the average ZEC across models is not only close to zero but very slightly negative (just under −0.1°C).

There is nonetheless a substantial range in estimated ZEC among the various individual models: anywhere from a cooling of −0.3°C to a warming of +0.3°C. Palazzo Corner et al. note, accordingly, that there is a roughly 66% likelihood that additional warming will be less than 0.3°C once zero emissions are reached. Conversely, that implies a 33% chance the warming could be more than this. Given we are currently at roughly 1.2°C warming relative to the pre-industrial era, that could mean reaching the oft-cited threshold for catastrophic warming of 1.5°C even if we were somehow to bring carbon emissions to zero today. While there is a good chance we would avert 1.5°C warming in that scenario, to paraphrase Clint Eastwood, we must ask ourselves one question: do we feel lucky?

Now, there are certainly some additional caveats to this story, and they are explored in some detail by Palazzo Corner et al. First of all, ZECMIP features only a subset of available climate system models, and the inferences drawn are quite limited beyond the 100- year time horizon, where the behavior of long-response components of the climate system—the ice sheets, the deep ocean, etc.—remains a bit vague. Unsurprisingly, there is a large degree of variation in model predictions beyond that time horizon, with some models indicating that additional warming could eventually kick in. Given the complexities of the ocean carbon cycle in particular and ocean mixing processes more generally (which are relevant for both carbon and heat burial), the seemingly coincidental balance between positive climate inertia and negative carbon cycle inertia is tenuous and subject to possible revision as scientific understanding continues to advance.

Another wild card is that other factors besides CO2 come into play when we examine future global temperature scenarios. Among these are sulfate aerosols (which exert a cooling effect) and black carbonaceous aerosols (which exert a warming effect) from coal burning and other short-lived greenhouse gases generated from human activity, such as methane, nitrous oxide, and lower atmospheric ozone pollution. In most scenarios, the effects of these competing short-term radiative constituents cancel each other out, constituting a near zero sum game as we phase out fossil fuel burning and the other underlying anthropogenic activities that generate them. But this depends on the details of policies impacting those activities, including, in the case of methane, agriculture, hydroelectric dam construction, and natural gas extraction. The cancellation is also dependent on us getting the radiative physics right. In the case of sulfate aerosols—particularly so-called “indirect effects” such as cloud nucleation—there is still substantial uncertainty. So, while long-term warming will largely be determined by what happens to CO2, these other contributors will matter too if the activities producing them continue.

Yet another caveat involves the precise magnitude of the carbon budgets that remain for avoiding critical warming thresholds. The amount of CO2 that can still be emitted for a 50% chance of staying below 1.5°C of warming is conventionally estimated to be roughly 100 GtC. At the current rate of emissions, we would run through that budget in less than a decade. Yet that estimate may be overly liberal as it is dependent on other assumptions. Among these is how we define the pre-industrial baseline relative to which net warming is measured. It has typically been taken to be the late 19th century (the mid-point of the first 50 years of available widespread surface temperature measurements). There is evidence, however, that human-caused warming began before that, perhaps as early as the mid-18th century. Taking into account the earlier human-caused warming potentially reduces the budget for averting 1.5°C warming by as much as 40% (5).

But the most significant caveat of all is that surface temperatures are not the only things that matter during the climate crisis. While some impacts, like extreme weather events, appear to be tied to surface warming, others, like rising sea levels and ice sheet destabilization, depend on the warming of the deep ocean. That would continue for decades and centuries to come (see Figure 1 from Palazzo Corner et al., 2023). Our earlier sink analogy, while useful for understanding the competing impacts on the warming level, is an imperfect one: even if surface temperature levels are constant, actual (rather than metaphorical) water levels will continue to rise for some time.

Moreover, as the ocean continues to absorb atmospheric carbon, ocean acidification—which impacts coral reefs and other calcareous ocean biota, such as mollusks and crustaceans—would continue to worsen, threatening food webs in the ocean. So, the penalty of procrastination remains, underscoring the importance of decarbonizing our societal machinery as rapidly as possible if we are to remain within our adaptive capacity as a civilization.

Nevertheless, this new study offers hope. At a time when climate advocates have become disillusioned by the lack of progress—and this is understandable given the “commitment gap” that still remains between what has been promised and what is required— this latest study reminds us that the obstacles to climate action are neither physical nor technological. At this point, they remain political. History teaches us that political obstacles can be overcome, so there remains both urgency and agency when it comes to the ongoing climate battle.

I often encounter people who maintain that it's pointless cutting emissions, because "it's too late", since the world will go on warming because of the oceans' thermal inertia.  Dr Mann's key point is that is wrong.   And that's very important — if we stop emissions now, there is a good chance that global temperatures will quickly stabilise.  It's the opposite of "too late".

Those who've sold their souls to oil and coal and gas want us to give up.  And we must not.

References

1. Elbein S. Catch-22: Scientific communication failures linked to faster-rising seas (2023). The Hill. Available at: https://thehill.com/policy/energy-environment/4057045- catch-22-scientific-communication-failures-linked-to-faster-rising-seas/ (Accessed July 10, 2023). 

2. Meinshausen M, Meinshausen N, Hare W, Raper SC, Frieler K, Knutti R, et al. Greenhouse-gas emission targets for limiting global warming to 2°C. Nature (2009) 458 (7242):1158–62. doi: 10.1038/nature08017 

3. Hertsgaard M, Huq S and Mann ME. How a little-discussed revision of climate science could help avert doom (2022). Washington Post. Available at: https://www. washingtonpost.com/outlook/2022/02/23/warming-timeline-carbon-budget-climatescience/ (Accessed July 10, 2023). 

4. Palazzo Corner S, Siegert M, Ceppi P, Fox-Kemper B, Frölicher T, Gallego-Sala A, et al. The Zero Emissions Commitment and climate stabilization. Front Sci (2023) 1:1170744. doi: 10.3389/fsci.2023.1170744 

5. Schurer A, Cowtan K, Hawkins E, Mann ME, Scott V, Tett SFB. Interpretations of the paris climate target. Nat Geosci (2018) 11:220–1. doi: 10.1038/s41561-018- 0086-8

Preventing a climate calamity is still possible.

 This is an informative video from Climate Adam.  He uses an analogy I've used before: a bathtub.  Virtually every year since 1850, the CO2 we push out into the atmosphere has risen.  Because the outflow from the atmosphere (natural carbon sinks) is less than what we're pumping into the air, the level of CO2 has risen.  Emissions have flatlined over the last 10 years, but they're still more than the removal of CO2 from the atmosphere via carbon sinks.  Using the analogy, the level of water (CO2) in the tub (atmosphere) is continuing to rise, just more slowly.  And thus temperatures continue to rise.  But if we could cut emissions so that they are the same as outflows, the level of water (CO2) would stop rising, and so would temperatures.

Adam makes the point that carbon sinks (where CO2 gets sucked out of the atmosphere) take up around 50% of emissions.  This is only a temporary help, because the carbon sinks (the sea, forests and marshes) are taking less and less out of the atmosphere.  They're filling up.  But it does mean that if we could cut emissions by 50%, the level of CO2 in the atmosphere, and therefore temperatures, would stop rising (or at least, rise more slowly), though we would still need to cut emissions over time to near zero.  It used to be thought that temperatures would go on rising for decades even after we achieved zero emissions, but this is no longer the scientific consensus.

Now, the good news is that together, emissions from electricity generation and land transport, on average across the world, are roughly 50% of total CO2 emissions.  If we could replace coal and gas in electricity generation, and convert the global car, lorry and bus fleets to electricity, we would have cut emissions by 50%.  In other words, stopping temperatures rising is achievable, and achievable over the next decade.  We would still have to achieve zero emissions, because with the oceans, the carbon sink reduction (the oceans offset and bury CO2) is offset by their thermal inertia — they will continue to release heat into the atmosphere as long as they are cooler than the atmosphere.   But switching to renewables and EVs would give us time to cut emissions from all the other more difficult sectors like cement, steel, air and sea transport and agriculture.

The other climate-warming gas Adam talks about is methane.  Methane comes from gas leaks, rubbish dumps, and cattle and sheep.  Methane has been rising fast, and shows no signs of peaking.  Over a ten-year time frame, methane is 80 times as potent a greenhouse gas as CO2.  But it quickly decays into CO2, so if we could cut methane emissions, the effects would be rapid.  One third of the rise in temperatures since pre-industrial times is from methane.  So, as we replace gas in electricity generation (and we will for now still need 5 - 10% gas generation to cover dunkelflaute events, because we don't have workable long-term storage), gas leaks will fall.  There are super emitters of methane from rubbish dumps.  And that's easy to stop: just cover your rubbish dumps with a thick layer of earth.  Finally, each of us can avoid beef, mutton and milk.  That's something we can directly do to cut emissions.  Turning vegetarian could be your single biggest step to cutting emissions!  (Buying an EV is another.)

The moral of all this is that we are far from helpless.  CO2 emissions have peaked.  Our task is to bend that curve down, until the level of CO2 in the atmosphere also peaks.  We have to turn the CO2 and methane taps off, and then we will actually be able to avoid a catastrophic climate future.

(One really scary factor driving increasing emissions is AI datacentres.  We need to stop their construction.  Now.)

Solar share exceeds 10%

 From a skeet by Dave Jones

In 2019, solar peaked at ~3%.  6 years later, it's three times as high.  If that growth rate continues, by 2031, solar will be providing 30% of world electricity demand.

(Why does it look as though solar peaks in the northern hemisphere summer? Because there is proportionally more land and more solar panels in the northern hemisphere than south of the equator) 

Sodium-ion even cheaper than I thought

I wrote a piece a month ago about CATL's new sodium-ion battery.  The video I link to provided more information, suggesting costs are even lower than I said.

The cost at cell level will be $19/kWh vs lithium-ion phosphate (LFP) of $55-$60/kWh.  CATL expects $10/kWh in a couple of years.  $45/kWh at pack level, less than half the cost of LFP.   Production can be carried out on existing assembly lines, so they don't have to rebuild the entire factory.  Any factory making LFP could pivot to sodium-ion at minimal cost and time.   

They will retain 85% after 3.6 million miles.  I said 80% in my earlier piece; so this is even better, meaning that after 50 years, 75% of the battery capacity will remain.  Their life will be 3-6 times longer than the best LFP packs.  Energy density has dramatically improved.  A year ago it was 120-140 Wh/kg, too heavy for EVs. The new energy density is 175 Wh/kg, better than BYD's current blade battery (160 Wh/kg).  They can be charged and used from -40 Celsius to +70 C.  And they use abundant materials: sodium, aluminium and carbon.  They are maintenance free.  They can be safely transported at zero charge, unlike lithium batteries.  CATL has also developed a pack made up of both sodium-ion and lithium-ion cells, combining the best qualities of both. 

Years ago, the rule of thumb was that if battery pack costs fell to $100/kWh, that would make EVs cost the same up-front as ICEVs (petrol vehicles).   (EVs are already much cheaper to run)  We have shot way past that point.  The introduction of sodium-ion batteries means that ICEVs will no longer be cost-effective, and production will cease.  

But this will also transform the grid.  The cost of storage has more than halved, and will halve again.   Solar is already the cheapest electricity for everywhere except high latitudes, and now it can be combined with enough dirt-cheap storage to provide base-load power.   That probably means 8 hours of storage, but storage will be so cheap that even 12 hours will be perfectly feasible and economic.  High latitudes will still need long-term storage, but when your EV dies, the batteries will still have another 50 years plus of life in them, and then they can be shipped to high latitudes to provide completely free long-term storage.

This spells the end of the fossil fuel economy.   Except for air transport and cement making, everything we now do with coal, oil or gas will be doable with cheap electricity from solar plus sodium-ion storage.

Even in the USA, even with 25% tariffs on imported batteries, the plunge in storage costs means that the EV and storage revolutions will continue.

Have emissions from electricity peaked?

 From EMBER.

Global [electricity] demand rose by 369 TWh (+2.6%) in H1-2025, compared with 731 TWh (+5.3%) in the same period last year. The smaller increase was due to a few factors, including a more measured pace of industrial growth in China and India, but also fewer heatwaves in May and June in India.

In China, demand grew by 198 TWh (+4.2%), compared with a much stronger increase of 326 TWh (+7.5%) in the same period last year.

Despite the smaller rise, the global demand increase in H1-2025 was close to the 10-year annual average of 2.7% for 2015-2024.

In India, demand growth was particularly low at 12 TWh (+1.3%), compared with +75 TWh (+9%) last year when heatwaves drove higher demand. Ember estimates that if weather during May and June 2025 had matched last year’s heatwave conditions, demand growth in India would have been closer to +3%.

The world’s four largest polluters accounted for 81% of the global demand rise in the first half of 2025: China 54% (198 TWh), the US 21% (76 TWh), India 3.3% (12 TWh) and the EU 2.4% (9 TWh).

Solar generation grew by 306 TWh (+31%) in the first half of 2025, its fastest absolute growth on record. If this pace continues, solar is on track to remain the fastest-growing source of electricity for the 21st consecutive year and to outpace wind growth in absolute terms for the fourth year in a row. 

Solar’s global share was 8.8% in the first half of 2025, more than doubling in the last four years, from 3.8% in 2021. In many countries, solar now makes up a considerably higher share of the electricity mix.Several economies set new records. Among the top 20 largest solar generators in absolute terms, seven countries — Hungary, Greece, the Netherlands, Pakistan, Spain, Australia and Germany — generated 20% or more of their electricity from solar in the first six months of 2025.

Hungary led with nearly 30% share of solar generation, ahead of Greece and the Netherlands, which both surpassed 25%, up from just over 10% only four years ago (in the first half of 2021). Meanwhile, based on Ember’s estimate, Pakistan saw the largest increase in share, from 4.4% in H1-2021 to 21.9% in H1-2025. The increase was driven by the rapid adoption of rooftop solar by households and businesses in response to high electricity prices, as reported previously by Ember.

Based on available monthly data, at least 29 countries generated over 10% of their electricity from solar from January to June 2025, up from 22 countries in the same period of 2024 and only 11 countries in the first half of 2021.

China remained the leader in absolute growth terms for the third consecutive year, accounting for 55% (168 TWh) of the global increase in solar in the first half of 2025. The US accounted for 14% (44 TWh), the EU 12% (37 TWh) and India 6% (17  TWh). In contrast, solar generation fell marginally in Japan by 1.4 TWh (-0.4%), partly due to record-high curtailment. Solar also declined slightly in Vietnam (-0.5 TWh, -1.7%).

Solar capacity additions also grew at a record pace, reaching a new high of 380 GW in the first six months of 2025 – 64% more than the 232 GW added in the same period last year. A record surge in May, driven by accelerated installations in China ahead of new pricing rules on 1 June 2025, was a key contributor. Overall, China accounted for 67% of total solar capacity additions in H1-2025.

Renewables overtook coal in the electricity mix for the first time on record, rising by 363 TWh (+7.7%) to 5,072 TWh in the first half of 2025. Their share increased to 34.3%, up from 32.7% in the same period last year. Coal fell by 31 TWh (-0.6%) to 4,896 TWh, with its share dropping to 33.1%, down from 34.2%.

My view on these figures:

The output of solar is rising by 30% per annum, and because solar panels and battery storage keep on falling in cost, that growth rate will continue, and may even accelerate.  This half year, solar output rose 306 TWh over the year, so in H1 2026, it could easily rise by 400 TWh, H1 2027 by 517 TWh, and in H1 2028, by 673 TWh.  Assume there is no acceleration in wind output, i.e., the annual increase in output remains at 100 TWh.   

World growth is likely to pick up.  The switch to EVs is accelerating, and datacentres are gobbling electricity.  Demand growth for electricity will be higher over the next year, and higher still in 2027. But, if world electricity demand rises by, say, 500 TWh in the year to H1 2026 (compared with 369 TWh in H1 2025), this will be satisfied by the increase in renewables supply.  Similarly, in H1 2027, demand could rise by more, say 550 or 600 TWh, and still be met by the increase in output from renewables.  By H1 2028, demand would have to rise by a record 770 TWh for renewables not to match this increase.  And thereafter, renewables will eat more and more deeply each year into generation from fossil fuels.

In other words, emissions from electricity generation have probably peaked.  

Declines will be small initially, but the stronger rise in electricity demand is (partly) to supply electricity for EVs. The decline in emissions from land transport will be accelerating.  

We are at, or are close to, the point where not just emissions from electricity generation, but also total global emissions, are peaking.  This is not a cyclical peak, caused by a recession or Covid.  It is a secular peak.  We have at last started on the long road to zero emissions.  Does that mean temperatures have stopped rising? No, unfortunately.  For that, we would have to cut emissions by at least 90%.  However, we're getting there.   Emissions could halve by 2045, and halve again by 2060. Definitely too long and too slow.  But we are at last on the right road.  Now we must try and bend the curve to get there faster.

Emissions have peaked

Two recent graphs, from different articles, have given me hope that we might yet avoid catastrophic global warming.  The first chart come from Carbon Brief, which I referenced here.

Let's dig deeper into the chart.  

It shows the smoothed year-on-year change in electricity demand in China, and the year-on-year change in the supply of electricity, broken down into fossil fuels (mostly coal, but some gas) and clean energy.  Over the last 20 years, there have been 5 times when production of electricity from fossil fuels has fallen: in 2009 (the GFC); in 2012/13 (the Euro crisis); in 2016 (a global mid-cycle correction which was quite severe in China); in 2022 (Covid lock-downs); and this year.

This year is the first time that fossil fuel production has fallen when electricity demand growth is strong.   Notice how the size of the pale blue bars (renewables) has got bigger and bigger, as China has installed exponetially increasing quantities of wind, solar and batteries.  Second, notice how electricity demand has grown, as (a) the economy grew, and (b) EV sales exploded, with each peak tending to be higher than the previous one.

Right now, an annual expansion in clean energy production of +-600 terawatt-hours (TWh) is enough to more than satisfy demand, causing fossil fuel generation to decline.   The 20-year average annual increase in demand is 400 TWh, while over the last 8 years or so, it looks about 500 TWh.  Obviously, if China's growth accelerates back to the heady rates on the early 2000s (10% a year), given how much richer China is now than then, the increase in demand could easily exceed 800 TWh.  However, growth is unlikely to accelerate back to those levels  The recent GDP trend growth rate is about 7%, and, in my judgment, slowing, as China deals with its property crisis.  (Also, China overstates its GDP growth data, so the real growth rate is lower.  The data for growth in electricity demand and supply are better quality.)  

The second chart came from an article by the ABC,  which I  commented on here.

The projected increase in new clean energy generation capacity for the next 2 years is about 600 TWh.  In other words, it's now more than the average rise in electricity demand.  

Of course, there is an economic cycle, with demand rising at 800 TWh in boom years, and reducing to 200 to 400 TWh in slower years.  So we may have a pattern of  falling emissions during low-growth years, followed by modest rises when the economy is stronger.  Yet this doesn't take into account the exponential growth in new wind and solar output over the last 7 years.   It's risen from 200 TWh to 600 TWh in just five years.  And although the forecast for the next two years is for only limited growth, the costs of solar and batteries contimue to decline rapidly.  The exponential growth will continue.  By 2028, new clean energy output will be increasing by 800 TWh a year, or more, so that even in high growth years, Chinese emissions from electricity generation will be falling.  

China is by far the world's largest emitter of CO2, causing over 25% of global emissions, compared with the US at 18%, and the EU at 17%.   Europe's and the USA's emissions peaked years ago:

Source: Our World in Data

What this means is this: if China's emissions have peaked, global emissions have probably peaked too.

It's true that the Trump administration has embarked on an utterly demented attempt to return the USA to the 1950s,  but cheap Chinese solar panels, batteries and EVs, are persuading the rest of the world (for example, Pakistan)---the other 80% of emissions---to switch to clean energy.  Plus, Trump's high-handed trashing of tariff and trade agreements means that the USA's opposition to carbon border taxes will not be effective.  If the USA can arbitrarily raise tariffs, then so can the rest of the world.  And they will.  Moreover, renewables are much cheaper than fossil fuels.  As electricity prices soar in the USA, cooler heads might prevail.

The peak in global emissions doesn't mean global temperatures will stop rising.  Emissions will have to fall by 90% for that to happen.  But what these devlopments do mean is that emissions are now in secular decline.  And the sustained fall in the costs of clean energy means that the decline will accelerate as renewables and EVs get ever cheaper.  As the impacts of catastrophic global heating worsen, the world will take stronger and stronger measures to slash emissions.

Temperatures will go on rising, but for the first time, it looks as if, by the 2040s, the decade-by-decade increases will start falling.

Some progress on emissions is happening

 From The Guardian

There is something of a reality check under way on the response to the climate crisis. It’s no secret that countries and corporations are far from living up to the goals set by international leaders at the landmark 2015 Paris agreement.

Unless there is a significant course correction, the ramifications will be far-reaching and often destructive. The second coming of Donald Trump and growing global instability has made a top-down injection of urgency at the pace needed harder to imagine. Optimism is harder to come by.

But that doesn’t mean nothing is happening.

It’s worth pointing this out because a narrative has started to take hold that renewable energy and other clean solutions have made little to no headway in displacing fossil fuels, and therefore are pointless. Fuelled by Tony Blair and the former US government adviser Daniel Yergin, and embraced by the fossil fuel industry and its lapdogs in the commentariat, it is used to attack zero emissions targets as a fool’s dream. In Australia, it is part of the backdrop as the Albanese government is lobbied over whether to set an ambitious emissions reduction target for 2035.

The reality, though, is more complicated. Here are some things worth considering if you hear climate action is pointless.

Clean energy is coming for fossil fuels

 

One line that has gained some traction this year is that the proportion of global energy supply from fossil fuels has barely moved over the past 35 years. The claim – bubbling away in The Australian, on Sky News [right-wing Murdoch media] and on social media – goes that dirty fuels provided 85% of energy in 1990, and still provide 80% today.

So much for progress, right?

But the Bloomberg New Energy Finance [BNEF]founder and self-declared conservative Michael Liebreich points out that this ignores an important factor.

The percentages referred to by fossil fuel advocates are for primary energy – that is, raw coal, crude oil, gas, wood, sun or wind. They do not refer to useful energy – energy that has been converted into a transportable form, such as electricity or refined petroleum, delivered to a consumer and then used to light their house or move their car.

This useful energy is the more relevant measure. And the process of processing raw fossil fuels into useful energy is, in many cases, not particular efficient. More energy is lost in generating at a remote coal-fired power plant and transmitting it to a home than if solar, wind or hydro was used. Petrol cars require much more energy to travel a kilometre than an electric vehicle does.

If we acknowledge this and consider useful energy alone, Liebreich says the amount of energy provided by fossil fuels is not 80%, but about 68%.

This is obviously still too high. But it won’t stay at this level. Despite all the talk of new coal plants still being built, they are playing in the margins. The International Energy Agency (IEA) forecasts that solar and wind will meet more than 90% of the global increase in electricity demand this year. Global generation from solar and wind energy is expected to increase by about 25%, from 4,000 terawatt-hours to more than 5,000. Next year it is expected to jump another 20%, past 6,000TWh.

The IEA projects that global renewable energy output – including solar, wind and hydro – will surpass coal output in either 2025 or 2026. For the first time in a century, the share of electricity coming from coal will have fallen to less than 33%.

Solar and wind will together be nearly 20% – up from 4% a decade ago.

A key question is if this growth in renewable energy will eventually reduce global fossil fuel use – as is necessary – or mostly just meet growing energy demand. Liebreich argues compellingly that fossil fuel use is set to fall. Using a simple model, he suggests it is likely to start falling in the 2040s and could be squeezed out of the system by about 2065.

That is not near fast enough to deliver the trajectory scientists say is needed to limit global heating since pre-industrialisation to 1.5C. But it is a well argued rejection of claims that a global transition isn’t possible.

China? It’s moving

 

With a population of 1.4 billion and having taken on a huge proportion of the world’s manufacturing, China is easily the world’s biggest direct national climate polluter, pumping out more than twice as much CO2 as the second-placed US.

Its story is mixed, as always. But the data show it is changing. An analysis for Carbon Brief by China experts Qi Qin and Lauri Myllyvirta found that coal’s share of the country’s power generation fell from 73% in 2016 to 51% in June this year. This happened as it continued to build new coal plants for a simple reason – it doesn’t run them at anything like capacity.

A significant moment came earlier this year when China’s national emissions fell for the first time, dropping 1% in the first quarter compared with a year earlier. Beijing needs to do much more if it is to meet its commitment under the Paris deal. Its next five-year plan for economic development, due this year, will be crucial.

Source: Carbon Brief
Note how renewable electricity generation has, for the first time since the deep 2009 recession, grown by more than the growth in electricity demand, even though demand growth has been strong.

Dirty car sales are down

 

According to Our World in Data, global sales of internal combustion engine cars – which run solely on petrol or diesel – peaked in 2016 at 80.47m. Electric and plug-in hybrid car sales in that year were just 780,000.

Last year, sales of dirty cars were 62.05m, a 23% fall. Electric and plug-in hybrid car sales had increased to 17.5m.

Put another way, nearly a decade ago only one in every 100 cars sold across the globe was electric. Now it is more than one in five. Elon Musk’s extraordinary self-own in damaging Tesla’s reputation may dent the pace of growth but it won’t stop it. China has little time or need for Teslas and is home to more than 60% of global EV sales.

Still a mountain to climb

None of this is to understate the scale of the problem. This column has reported before on the big step-up in global heating since June 2023. Averaged across the globe, every day in 2024 was at least 1.25C hotter than preindustrial levels, and three-quarters were 1.5C hotter.

Extreme weather events are becoming more damaging. Feedback loops (melting permafrost and huge wildfires) are releasing large additional amounts of CO2, accelerating the problem. Governments have barely started to acknowledge the expected increase in economic, societal and environmental costs that will hit productivity – the current focus of the Australian political class – and so much else.

It’s hard to overstate how much there is to be done. But don’t believe self-interested arguments that action is impossible, or will be for nothing.

 

Wind + Solar provide 26% of China's electricity

 From Nicholas Fulghum

Wind and solar generated more than a QUARTER of China's electricity for the first month on record In April 2025, 26% of China's electricity generation was produced by wind and solar according to our latest

@ember-energy.org

data. Wind: 13.6% Solar 12.4%

As the EMBER piece says: 

The April record was driven by both wind and solar hitting individual record high shares. Wind power accounted for 13.6% of generation while solar contributed 12.4%. The rise of solar power in particular has been remarkable. The share of solar power has tripled in the last five years, from just 4.1% in April of 2020. In 2024, China installed more new solar capacity than the rest of the world combined, more than tripling its rate of installations in just two years, from around 103 GW (DC) in 2022 to 333 GW in 2024. Installations have continued at pace in 2025, with 72 GW of new solar added in Q1 alone, up 18% from Q1 2024, according to Ember’s monthly wind and solar capacity data.

The rapid build out of solar capacity in China has pushed not only the share, but also absolute solar generation to new heights. In April 2025, China hit a new record of 96 TWh of solar generation, surpassing the previous record of 89 TWh set in August of 2024. This record may soon be surpassed again as summer conditions further boost output. 

The growth in renewables is also reshaping the overall generation mix. Fossil fuel generation has already declined by 72 TWh—or 3.6%—year-on-year across the first four months of 2025, a shift that’s beginning to show structural signs.

The rate at which wind and solar are increasing means the rise in output from renewables now exceeds the rise in total demand (current running at +-3% per annum), even with electricity demand increasing because of EVs and PHEVs.   Which means, in turn, that China's emissions have peaked.  

Caveats:  growth may soar this year or next, or, for some inexplicable reason, wind and solar will stop growing.  Solar panels continue to decline in cost, and battery costs are falling even faster, meaning solar can be "firmed" easily and cheaply, so solar, at least, is likely to continue growing fast. 

  Note how wind and solar have different seasonal patterns, which means that, combined, less of both is required.  For now, gas will still be required to balance the grid when renewables are low, but the rise in EVs/PHEVs and falling capacity utilisation at coal power stations, means that China has passed peak coal and peak oil.   Since China produces +-25% of the world's emissions, that may mean that world emissions have also peaked. 

Total solar installed doubles in 2 years

 From Kees van der Leun

After decades of solar PV deployment, the world crossed the 1 TW (a million MW) line in 2022. Just two years later, after adding 0.6 TW in 2024, we already crossed the 2 TW mark too!
#SolarPV #solarenergy #renewables

It took 22 years for cumulative solar installed to reach 1 terawatt.  It took just 2 years for the next terawatt.  And I expect over the next 2 years, another 2 terawatts of solar will be installed.  Total cumulated solar is doubling every two years.  

Why?  First, solar continues to plunge in price.  Second, how much solar you could have in your grid was limited because there's no solar at night.  But with storage costs plunging, that's less and less of a constraint.  Solar farms are already routinely built with 4 hours of co-located storage.  In a couple of years, that will be 8 hours.  

Note:  this is not new solar installed each year, though that is also growing exponentially.  It is the cumulative total of all solar panels installed.

Electricity generation is going to transition to zero carbon much faster than even I, an optimist, have been thinking.

Is there any hope at all?

There are some extraordinary things happening in the renewables space.

1. Solar power is up a lot (it varies by country) almost everywhere.  The cost of solar continues to decline, and because the cost of storage is plunging, "firming" solar electricity is becoming easier and cheaper.

2. CATL has introduced improved sodium-ion batteries. Sodium is roughly 1/5th as costly as lithium, so sodium-ion batteries will be much cheaper than lithium-ion. They also have a much longer life, theoretically allowing cars to travel 3 million miles before the batteries wear out. These new batteries will have 10,000 cycles, which will mean that even if they are charged and discharged 100% every day, they will still last 27 years.  Fantastic for stationary (grid) storage.  

3. EVs continue to make up an ever larger proportion of total car sales. In China, 1/3rd of the world's car market, they are +-50%, heading straight towards 100%. EVs (from China) now have the same sticker price as petrol cars. For example, here in Oz, the cheapest BYD Dolphin costs the same as the cheapest petrol Toyota Corolla. As battery prices plunge, EVs are only going to become ever more attractive.


Emissions from land transport and electricity generation are just under 50% of total global emissions. It seems plausible that these will have nearly ended by 2040, putting us halfway down the road to zero emissions. We need to do more (stop eating red meat, replace gas/oil heating with heat pumps/electrical heating, fix cement, steel and air travel, stop land clearing) to bend that curve towards a better outcome, but for the first time in years, I feel optimistic that we at last have a chance of avoiding catastrophic climate change.  

What can you do to help?  You can cut your personal emissions, by as much as 20-30%, by becoming vegetarian, or at least, stopping eating beef and mutton, and not using milk.   If mankind did that, we would cut emissions by +-70%, adding together the decline in emissions from agriculture and transport and electricity generation.  The more we cut emissions, the sooner temperatures will stop rising.

It has been possible to argue that anything we do is pointless, because China's emissions have just kept on rising.  But this year, or next, China's emissions, as the country installs more and more solar, and EV sales continue to explode, will peak and start falling, and that particular excuse for inaction will disappear.

Let's do this.  

US wind and solar now 25% of all electricity

From John Hanger

Good morning with good news: US wind & solar surge, generating 83 TWh in March 2025, up ~20% from 69 TWh in March 2024.

W&S were 24.38% of US electricity in March 2025 March W&S generation: 2025 83 TWh 2024 69 TWh 2021 52 TWh 2020 39 TWh 2015 18 TWh 4X since 2015 & 2X since 2020!

Everywhere you look, you can see wind, or solar, or wind and solar rising steadily.  In some countries, it will reach its markets share, i.e., whatever is left over after hydro and nuclear with a few years, in others it will take longer.  But we're getting there.

BYD leads unstoppable charge

BYD's plug-in hybrid, The Shark

 

From The Driven 

In 2024, China registered 31.436 million new automobiles, a rise of 4.5 per cent over the previous year, with the growth of NEVs (new energy vehicles) jumping an astonishing 35.5 per cent.

In the passenger vehicle market, China achieved an annual penetration rate of NEVs of 47.6% throughout 2024, with the percentage of new sales exceeding 50% for five consecutive months in the second half of the year.

That trend has continued into 2025, with China’s February NEV sales reaching 892,000, up 87 per cent from February 2024. BEV and PHEV sales were up 85% and 90% year on year respectively, far outpacing the overall demand growth (including ICE vehicles) of 34 per cent.

As the country’s biggest car maker BYD says, the facts demonstrate the unstoppable trend of electrification and accelerated replacement of ICE vehicles with NEVs.

As the world’s largest NEV producer, BYD is leading the charge both domestically and internationally on transforming the possibilities of electrified mobility and household electrification. Its rival, Tesla, has effectively left the race when it comes to sales growth.

The BYD profit report released overnight reveals that BYD generated RMB 777.1 billion ($US107 billion) in revenues in 2024, up 29.02% yoy, driven by a 40% yoy growth in NEV sales.

This translated to a 34% yoy growth of net profit to RMB 40.3bn ($US5.55bn) over the year for BYD, even as it invested RMB 54.2bn ($US7.48 billion) into R&D in 2024, taking its total investment into R&D to RMB 180bn ($US24.83 billion), most of it into its world-leading technology in batteries, electronics and EVs.

The company has 20,000 R&D engineers, and submits an average of 45 patent applications and 20 patent licenses every day. One of the latest is the ‘Super e-Platform’, enabling 1,000 kW charging power. Stepping into the era of “charging as fast as refuelling” with the ability to charge 400km in just 5 minutes.

The impact of that R&D is there to see. Battery prices have fallen 82% in the last 10 years alone. In the same time, battery densities have risen 5-fold.

In 2024, lithium-ion battery prices fell a further 20% to a record low of US$115/kWh as manufacturing overcapacity continues to surge.

In 2024, 3,100 GWh of fully commissioned battery-cell manufacturing capacity was online, more than 2.5x that of annual demand. This has driven massive demand growth for EVs and stationary energy storage (BESS) systems globally, with China continuing to dominate.

BYD is already showing incredible growth in 2025, with sales up 93% in the first two months of the year to 623,300 vehicles.

While Tesla’s profitability contracted over 2024, and its share price continues to dive as the US regresses on climate, clean energy and trade, BYD’s share price is up more than 51% in 2025 on the Hong Kong Exchange.

China was already the winner. Now it is clear, the runner-up has left the race. Incredible to see the EV revolution and China’s leadership in real time.

I've been saying for nearly a decade that the growth of EVs to market dominance was inevitable.  You just had to extend the lines plotted on log scale to see what was likely.

What I got wrong was that I assumed that Tesla would remain the market leader.  But Musk became obsessed with right-wing culture wars, and took his eye off the ball.  Anybody who has ever managed a business will know that that is fatal.   Market leadership has now switched to BYD, and more broadly, China.  The US had the lead; and together Musk and the Republicans have thrown it away.  Even assuming a changed administration in 2028, the US auto industry's lag behind China will have expanded to 5 years.   With the speed with which the market is shifting, that might as well be a lifetime.  Things are moving so fast in China that competitors will be unable to respond.

BYD is also driving down battery prices for grid storage.  And this will accelerate the replacement of coal and gas by solar with storage.   Learning curves with a vengeance, fuelled by billions of dollars of Chinese research.  Under these circumstances, no rational investor will put money into coal, oil or gas.  They're done.  Over.  Antediluvian.  As outdated as the Lockheed Constellation, or the Vickers Viscount, technological marvels of their time.   

So, whatever Trump or the Republicans or Big Oil think or do, electricity generation and road transport will go fully electric.  And as battery energy density rises, so will rail transport, shipping, and (eventually) air transport.  50% of global emissions will be eliminated.

[BYD's sales include plug-in hybrids.  These will surely be replaced with fully electric vehicles as cost falls and energy density increases.  At some point the cost of a second engine will outweigh the cost of bigger batteries, while at the same time, the rapid deployment of fast chargers will remove range anxiety.]

 

Solar is king

From Our World in Data

 

In 2004, it took the world a year to add one gigawatt of solar capacity.  Now it takes a day.  By 2030, it will take 2 hours.

Note log scale.  With a log scale, constant rates of change show as a straight line.

Half the world's electricity to come from solar by 2035

 I've talked about the S-curve before.  At first, the new technology has a tiny market share.  But let's say it grows by 15% a year.  The market share will rise four-fold in 10 years, and 66-fold in 30.   At a 20% growth rate, market share will rise 6-fold in 10 years, 237-fold in 30 years.   Naturally, as market share gets closer to 100%, growth rates slow.  Hence the S-curve.

From The Electric Viking:

Close to tipping point in generation

 From EMBER

They haven't released 2024 data yet.  But assuming the share of clean electricity rises by just 10% per annum, that means it will rise by 4 percentage points a year.  This is faster than the rise in global electricity demand.  Of course, from year to year, demand will fluctuate according to the business cycle, while green supply will fluctuate because of droughts (in the case of hydro).  But the average over a couple of years will show that demand is rising by 3 to 3.5% per annum, while green supply is rising faster than that.

So, even if fossil fuel generation didn't peak in 2023, it will peak in 2024 or 2025.  Since EVs and PHEVs continue to rise as a percentage of new car sales, and therefore of the existing fleet, and since electricity generation and transport together contribute to ~50% of emissions, total global emissions have prolly peaked or will soon.   That's good news.  What's not good news is that they won't be falling anywhere near fast enough.  But at least they will be falling.

A new powder which captures CO2

The carbon-capturing powder, pictured on Berkeley's campus. Photograph: Zihui Zhou/University of California, Berkeley

From The Guardian

An innocuous yellow powder, created in a lab, could be a new way to combat the climate crisis by absorbing carbon from the air.

Just half a pound of the stuff may remove as much carbon dioxide as a tree can, according to early tests. [Over the tree's life? Over a week?]Once the carbon is absorbed by the powder, it can be released into safe storage or be used in industrial processes, like carbonizing drinks. [Aerating drinks doesn't permanently remove CO2 from the atmosphere, since the gas is released when the bottle or can is opened.]

“This really addresses a major problem in the tech field, and it gives an opportunity now for us to scale it up and start using it,” says Omar Yaghi, a chemist at the University of California, Berkeley. It’s not the first material to absorb carbon, but “it’s a quantum leap ahead [of other compounds] in terms of the durability of the material”.

The powder is known as a covalent organic framework, with strong chemical bonds that pull gases out of the air. The material is both durable and porous, and can be used hundreds of times, making it superior to other materials used for carbon capture.

Yaghi has been working on similar materials for decades. It’s part of a broader push to collect tiny amounts of carbon from the air – either from power plants or from air around cities. Yaghi’s research with Zihui Zhou, a graduate student in his lab, and others was published in the journal Nature last month.

In the lab, Yaghi’s team tested the new powder and found that it could successfully absorb and release carbon more than 100 times. It fills up with carbon in about two hours, and then must be heated to release the gas before starting the process over again. It only requires a temperature of about 120F to release the carbon; that makes it an improvement over other methods, which require a much higher temperature.

That feature means places that already produce extra heat – such as factories or power plants – could use it to release the gas and start the cycle again. The material could be incorporated into existing carbon capture systems or future technology.

Yaghi says he could imagine a future in which people build large plants using the material in every city of 1 million people or more around the world. He has plans to scale the use of this type of carbon capture with his Irvine, California-based company, Atoco, and believes the powder can be manufactured in multi-ton quantities in less than a year.

Shengqian Ma, a chemist at the University of North Texas who was not involved in the new work, says this technology could be gamechanging. “One longstanding challenge for direct air capture lies in the high regeneration temperatures,” he says, adding that the new material can substantially reduce the energy needed to use direct air capture, making it “very novel” and “very promising”.

“We need to reduce our greenhouse emissions, and we need to do it fast,” says Farzan Kazemifar, an associate professor in the department of mechanical engineering at San Jose State University who was not involved in the new study. “In the short term, replacing large emitters of carbon dioxide – like coal power plants – with renewable electricity offers the fastest reduction in emissions. However, in the long term, in case the emissions don’t go down at the desired pace, or if global warming effects intensify, we may need to rely on technologies that can remove carbon dioxide from the atmosphere, and direct air capture is one of those technologies.”

Still, removing carbon from the air remains difficult, and as with all early-stage lab-scale studies, the challenge is scaling up the system for pilot studies. The concentration of carbon dioxide, though it is increasing, now stands at about 400 parts per million, or 0.04%. That means that any technology to capture the gas from the air requires moving huge volumes of air – and that requires large electricity consumption for running fans, says Kazemifar. “I believe the high energy intensity of the process is the main challenge with all [direct air capture] technologies.”

Having to heat this material to just 120 F (49 C) means it will use far less energy than other substances/techniques.  That amount of heat can be produced simply by sunshine with the help of mirrors or lenses.  The air in a sealed car will reach 120F in half an hour when the air outside is just 80F.  The stuff can be reused at least 100 times.  In other words, direct air capture (DAC) will become much, much cheaper.   The second half of "carbon capture and storage" is the storage.  In this piece, which I wrote in 2016, I discuss converting CO2 to rock, by dissolving it in water and injecting it into 
basaltic rock, which is full of air holes.  Within 2 years, the holes fill with a stable chalky rock, which has been made from the CO2.  Basalt is fairly widespread across the globe.  In other words, as soon as this product is commercialised, we will be able to extract CO2 from the atmosphere and safely store it underground at low cost.  In fact, with luck, the European price on carbon, currently about US$70/tonne, might be enough to cover the costs.

Something to be hopeful about.

Emissions from electricity peaking

From EMBER

Renewables generated a record 30% of global electricity in 2023, driven by growth in solar and wind. With record construction of solar and wind in 2023, a new era of falling fossil generation is imminent. 2023 was likely the pivot point, marking peak emissions in the power sector.

The renewables revolution – led by solar and wind – is breaking records and driving ever-cleaner electricity production. The world is now at a turning point where solar and wind not only slow emissions growth, but actually start to push fossil generation into decline.

Indeed, the expansion of clean capacity would have been enough to deliver a fall in global power sector emissions in 2023. However, drought caused a five-year low in hydropower, which created a shortfall that was met in large part by coal. Nonetheless, the latest forecasts give confidence that 2024 will begin a new era of falling fossil generation, marking 2023 as the likely peak of power sector emissions.

01  Renewables provided 30% of global electricity for the first time

In 2023, growth in solar and wind pushed the world past 30% renewable electricity for the first time. Renewables have expanded from 19% of global electricity in 2000, driven by an increase in solar and wind from 0.2% in 2000 to a record 13.4% in 2023. China was the main contributor in 2023, accounting for 51% of the additional global solar generation and 60% of new global wind generation. Combined with nuclear, the world generated almost 40% of its electricity from low-carbon sources in 2023. As a result, the CO2 intensity of global power generation reached a new record low, 12% lower than its peak in 2007.

02  Solar was the main supplier of electricity growth in 2023

Solar is leading the energy revolution. It was the fastest-growing source of electricity generation for the 19th year in a row, and surpassed wind to become the largest source of new electricity for the second year running. Indeed, solar added more than twice as much new electricity as coal in 2023. The record surge in installations at the very end of 2023 means that 2024 is set for an even larger increase in solar generation.

03  Hydropower fell to a five-year low, preventing a fall in emissions in 2023

Drought conditions resulted in a record fall in hydropower generation, which dropped to a five-year low. Under normal conditions, the clean capacity added during 2023 would have been enough to enable a 1.1% fall in fossil generation. However, the shortfall in hydropower was met by an increase in coal generation, which led to a 1% increase in global power sector emissions. 95% of the coal generation rise in 2023 occurred in four countries that were severely affected by droughts: China, India, Viet Nam and Mexico.

04  Demand growth slowed in 2023, but in future it will only go up

Global electricity demand rose to a record high in 2023, with an increase of 627 TWh which is equivalent to adding the entire demand of Canada (+607 TWh). Nevertheless, the 2023 increase of 2.2% was below the average for recent years, due to a pronounced decrease in demand in OECD countries, notably the US (-1.4%) and the EU (-3.4%). In contrast, the rapid demand growth in China (+6.9%) was equivalent to the total global growth in demand in 2023. More than half of the electricity demand rise in 2023 was from five technologies: electric vehicles (EVs), heat pumps, electrolysers, air conditioning and data centres. The spread of these technologies will accelerate the growth in electricity demand, but overall energy demand will decline as electrification is much more efficient than fossil fuels.

05  A new era of declining power sector emissions is about to begin

Ember forecasts fossil generation to fall slightly in 2024, leading to larger falls in subsequent years. Demand growth in 2024 is expected to be higher than in 2023 (+968 TWh) but clean generation growth is forecast to be even greater (+1300 TWh), leading to a 2% fall in global fossil generation (-333 TWh). Already the rollout of clean generation, led by solar and wind, has helped to slow the growth in fossil fuels by almost two-thirds in the last ten years. As a result, half the world’s economies are already at least five years past a peak in electricity generation from fossil fuels. OECD countries are at the forefront of this, with power sector emissions collectively peaking in 2007 and falling 28% since then.

Note the exponential growth of solar. 
Falling battery pack as well as falling solar panel costs means this will continue.

Before you get all excited, this forecast of falling emissions from now on only applies to emissions from electricity generation.  They are about 1/3rd of total emissions, globally.   Also, to stop global temperatures rising, emissions don't just have to start declining, they have to stop.  Until they do, or at least fall to 5 or 10% of current levels, temperatures will just go on rising.  The good news is that if emissions do start falling, they'll rise more slowly.