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.)
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