Weatherdem's Weblog

Bridging climate science, citizens, and policy

U.K. Paper: Analysis Indicates 2C Warming All But Inevitable

Leave a comment

A set of papers were temporarily made available to the general public in advance of the COP16 meeting in Cancun.  They present quite a sobering view on just how close we are to locking the planet into dangerous global warming scenarios.  One of the papers has this critical set of statements:

The analysis suggests that despite high-level statements to the contrary, there is now little to no chance of maintaining the global mean surface temperature at or below 2◦C. Moreover, the impacts associated with 2◦C have been revised upwards, sufficiently so that 2◦C now more appropriately represents the threshold between ‘dangerous’ and ‘extremely dangerous’ climate change. Ultimately, the science of climate change allied with the emission scenarios for Annex 1 [industrialized] and non-Annex 1 nations suggests a radically different framing of the mitigation and adaptation challenge from that accompanying many other analyses, particularly those directly informing policy.

The significance of that first statement cannot be overstated.  For the first time, a research group has made the assessment that, despite the climate research community’s decades’ worth of warnings, policy makers have nearly locked the globe into a significant warming scenario.

As additional effort has been undertaken to determine in more detail what 2◦C warming entails, it has become clearer that even that seemingly small amount of warming is extremely dangerous to human societies and the planet’s ecosystems.  We are now at the threshold past which radically new approaches to reduce the threat that global warming presents will begin to no longer be voluntary, but required.

Because policy makers have thus far refused to seriously assess the risk associated with various levels of warming, efforts to quantify the probability of exceeding those levels of warming have unfortunately been biased too low.  To date, the probability of surpassing 2◦C have resided between 5% and 33%.

This paper investigated a range of emissions scenarios, maximum cumulative CO2-equivalent values and assorted distributions of those max CO2-e values by industrialized and non-industrialized nations.  The majority of the scenarios and maximum values are physically unrealistic (CO2-e emissions peaking for industrialized nations in 2007, for instance), and yield probabilities of exceeding 2◦C between 36% and 52%.  Of the remaining scenarios, there is an 88% probability of exceeding 2◦C.  Unfortunately, those scenarios include industrialized nations’ emissions peaking in 2017 – even that isn’t likely to happen in the country that is the world’s largest contributor to emissions, the U.S.  I haven’t seen realistic evidence that other industrialized nations’ emissions reductions will be enough to offset the U.S.’s emissions in the next 5-10 years.  I would be pleased to discover that is the case, of course.

The paper does offer this incredibly blunt statement in its conclusion:

However, given the CCC acknowledge ‘it is not now possible to ensure with high likelihood that a temperature rise of more than 2◦C is avoided’ and given the view that reductions in emissions in excess of 3–4% per year are not  compatible with economic growth, the CCC are, in effect, conceding that avoiding dangerous (and even extremely dangerous) climate change is no longer compatible with economic prosperity.

“Avoiding dangerous climate change is no longer compatible with economic prosperity.”  How economically prosperous will anybody be once extremely dangerous climate change is affecting the globe?  What this means in the real world is that the time frame during which economic prosperity would not suffer is likely to be over.  Any actions we take to meaningfully deal with global warming will, at least in the short term, be economically painful to undertake.  Better that though, than letting global warming run rampant and destroying economies along with our civilizations.

Cross-posted at SquareState.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s