Friday, March 4, 2016

The 8.2 ka event

A most interesting blog post from RockyRex, about an anomalous episode during the warm up from the last ice age, when, for a period lasting just 150 years, global temperatures plummeted before resuming their up trend.  Scientists now think that this was due to the catastrophic failure of an ice dam which had been keeping a very large body of meltwater behind it.  When this fresh water flooded into the sea, it affected the thermohaline circulation of sea water.  Fresh water is less dense than salt water, so it remained on the surface of the sea, displacing the gulf stream further south and weakening it.  Northern hemisphere temperatures dropped 2 C in a couple of decades, and the sea level rose by between 0.4 and 2.1 metres.

The current rapid melting of Greenland's ice cap appears to be producing a similar "cold blob" in the Atlantic, and the Gulf Stream has slowed.  If this process gains strength--very likely as Greenland's melt accelerates--there will be a temporary (100 years plus?) cooling of the North Atlantic.  No doubt the denialists will say, see, we told you so, the world is cooling.  What seems to be certain though, is that this "cold blob" combined with much warmer seas around it, is responsible for the record floods in Scotland and Northern England over the last few years.

Read more of RockyRex's post here.


Thursday, March 3, 2016

Massive February heat spike

Still preliminary data--most of the agencies which calculate global temps don't release their official calcs until the middle of the month.  But it looks as if February had the highest anomaly (relative to the average for the 20th century) higher even than January's.  And December's.  And ....  In fact the highest ever.  1.4 C above the baseline.   Already.

OK, it's just one month.  And it's an el niño year, but it's still far higher than the last major el niño year, 1998.  The linear trend per decade has been 0.21 C.  We have just 2 decades to stop global temperature averages from rising by less than our target of 1.5%.   And still the denialists deny.

Yet we could, if we put our minds to it, slash carbon emissions to zero within 20 years.

Source



Wednesday, March 2, 2016

India and renewables

I hadn't seen this before, but it is certainly significant.  Instead of a carbon tax, India taxes coal directly, both local production and imports.  And they've just doubled this tax. Again.

The coal tax is instead of giving subsidies to renewables, and is designed to reflect the negative externalities of coal.  Its net impact is to make renewables even more attractive.  Solar is already cheaper than imported coal.  Within 5 years it will be cheaper than domestic coal too.  India has already started a rapid shift into renewables   The rise in tax will accelerate this shift.

It's good news.  The world's four largest emitters, China, the US, India and Europe have all started to aggressively decarbonise their economies.  These 4 as a group produce just under 60% of total emissions.  And as the costs or renewables slide, this switch will accelerate.  This is a tipping point. Every year from now on, renewables will get between 10 and 15% cheaper.  Their costs advantage will just get better and better.   Industrial scale solar is now around 5 (US) cents per kWh, wind around 3.6, CSP as low as 10 cents.   These are lower than or close to coal (9.5 cents per kWh)  and gas (7.5 cents per kWh) (Source.  Note that the costs for renewable sources in the data table seem to be way out of date, or at least, differ substantially from recent signed contracts)

18 months ago, I argued for an absolute cut in developed country emissions of 4% a year, if we were to get to zero emissions by 2100.  I think we have to do better than that, given the recent acceleration in global temperature increases.  I'd like to see a 75% cut by 2050, which for the world as a whole is a cumulative 6% per annum.  For developed countries, my guess would be that to allow for some growth in developing countries, the decline would have to be more like 8% per annum.  That won't happen short term, because the percentage of renewables has to ramp up.  But for places like Germany, already at 40% renewables in their grid, a rise of 4% a year (the recent rate of inrease) in the percentage of electricity generated from renewables will mean zero emissions from electricity in 15 years.  If we can replace petrol and diesel transport with EVs then a 75% cut by 2050 in total emissions will be easily doable.

 I am now convinced that this will happen, because renewables costs are falling so rapidly, and because after the Paris Climate Agreement, the world has finally realised that something must be done.  India is showing us how.

Tuesday, March 1, 2016

Trump & the GOP establishment


Cartoon by Ed Wilson

Delhi's air pollution worse than Beijing's

This chart from IEEFA shows just how bad air pollution is in Beijing and New Delhi.  China is serious about reducing air pollution: it's racing to replace coal power plants with wind and solar, and heavily promotes electric cars.

India not so much.  But switching electricity generation to renewables is a no-brainer, since they are now cheaper than coal.  Even India is doing it.  

That still leaves diesel lorries and buses.  But EV sales are exploding: the total number of EVs globally doubled last year to 1.3 million.  Annual sales rose 68%.  To reduce air pollution, we mustn't just go renewable in power generation, but also switch to electric cars, lorries and buses.  And the way battery costs are falling, that too will soon be a no-brainer.  But we need to move more rapidly to de-carbonised economies, and that means, for now, subsidies for EVs, funded by rising taxes on petrol and diesel.