Whistling past the climate change graveyard by David Atkins

by David Atkins, Digby's Hullabaloo, September 14, 2012

There's a big new academic paper by Bernie, Gohar and Lowe on behalf of a number of academic organizations providing advice to the British government on the subject. The result?

Two of the results presented here may stimulate media interest in this report. The first is that the lowest feasible temperature target, achievable under current understanding of emissions reductions, for 2100 is 1.6 °C. The second concerns a delay in the timing of peak emissions and the effect this has on either overshooting the 2 °C target, or meeting it by deploying stringent emissions reductions (for example with BECCS which will effect land use and agriculture).

In short, there is basically no way to avoid the 2 °C threshold, which is already incredibly dangerous.

The details:

This study develops over 150,000 plausible mitigation pathways and assesses their climate outcomes to examine the potential flexibility of emissions pathways leading to climate targets of 1.5-3.0 °C above preindustrial levels. As well as a much fuller coverage and analysis of possible emission pathways than was available previously, the report’s analysis includes the possibility of large scale negative emissions technology later in the century, in line with the estimates of the land available for bio-energy from Committee on Climate Change’s 2011 report on bio-energy and DECC’s estimates of potential efficiency of bio-energy carbon capture and storage (BECCS). Probabilistic impacts projections for 2050 and 2100 are also presented from a new modelling framework developed under AVOID, to aid interpretation of the relative climate impacts at different levels of climate change.

The main finding of the report are: 

The lowest median 2100 temperature target found to be possible in this study was 1.6 °C. This was only found possible with a peak in global emissions in 2014, and emissions reductions rates and long-term negative emissions at the very limit of what is currently understood to be feasible.

In other words, even if we basically stopped emitting all reasonable carbon right now, we'd still see a 1.6 °C mininum in warming.

More:

Without negative emissions in the longer term, a 2 °C target by 2100 was the lowest found to be possible in the current framework. This requires the highest emissions reduction rates currently considered feasible (3.5% per year) and a peak in global emissions before 2016. Less than 1% of the scenarios that lead to 2 °C of warming by 2100 and which do not include net negative emissions have reached their maximum global average temperature and started to cool by 2100. Of those scenarios meeting 2 °C in 2100 which do include negative emissions, over 90% have reached their peak warming and started to cool by 2100.

Temperature targets a few tenths of a degree above 2 °C in 2100 introduce significant flexibility in the range of emissions pathways that are consistent with a given target, allowing lower reductions rates of emissions, later peaks in global emissions and a larger long-term minimum of global emissions.

Future historians are going to look back at us and declare us collectively insane. We have:

(1) The worst financial crisis in 70 years, with mass unemployment across the world, caused by a parasitic and near useless casino financial sector;

(2) A global climate change crisis that quite literally affects humanity and the fate of civilization as we know it; and

(3) Energy and efficiency technologies that can help curb carbon emissions while putting millions of people to work.

All it would require is just a little cooperation from the countries around the world so very busy protecting their own "national" interests, and the subordination of the temporary interests of the global jet set plutocrats to the future of the species. It's not even that the billionaires wouldn't still be billionaires. They'd just have a little less, in exchange for a decent middle class and protecting our collective future.

But no. Instead, we're going to spend this generation bluffing over which nation-state can put up the most pointlessly aggressive geopolitical stance against the other, aided and abetted by a global network of insecure plutocrats afraid they might have to give up their 3rd yachts.

It's sickening, and I have no idea what to do about it except holler as loudly as I can. The system is totally broken. Conservatives think that Jesus/Moshiach/Madhi is coming to save them or figure they'll be dead and therefore don't care. And way too many liberals want to revert to the sort of nation-state protectionism and environmental localism that will only accelerate the problem.

http://digbysblog.blogspot.com/2012/09/whistling-past-climate-change-graveyard.html

1 COMMENT:

Anonymous said...

The numbers above are far too conservative. If we ceased all fossil fuel combustion today, the temperatures (above pre-industrial) in a few decades would reach about 2.5 C, for three reasons. First, we have already increased by 0.8 C. Second, the 'climate commitment' due to thermal inertia is about 0.6-0.7 C. Third, no more fossil sulphates will be produced to mask the full heating effect, and there will be an 'aerosol forcing' of somewhere between 0.5-1.5 C; the dispersion is due to disagreement among the experts as to the exact increase. On average, this totals 2.5 C. Note that this number is only from fossil fuels already used, and it does not take into account the many positive feedbacks we are already seeing today (e.g., methane).

In more ways than one, we are already 'toast', unless we can find the equivalent of a successful 'Hail Mary' pass.

September 16, 2012 8:53 AM