From Paris to NY: Cap Global Warming at 1.5 degrees c, not 2


From Paris to NY: Cap Global Warming at 1.5 degrees centigrade, not 2

One of the three major fights that will take place at the “final” Paris global treaty climate change summit is whether to cap global warming at 2 degrees centigrade or 1.5% degrees. The rather disastrous Copenhagen meeting in 2010 included 2 degrees as the target but the failure to resolve the issue was a major factor why the meeting flopped. There was sufficient pushback by 130-plus countries at the Lima gathering to formally reopen this issue.

(Other major fights will be over financial commitments from the rich to developing countries to assist with climate, and on how the pledges to reduce emission will be enforced. The pledges come no where close to keeping emissions at even 2 degrees)

The 2 degree limit means reducing global emissions by about 3.5% annually. The 1.5 degree limit requires reductions of about 7.1%,

This has major implications as to what goals should be set in NY for how quickly one transitions away from fossil fuels. NYS has been one of the world leaders in emitting excess greenhouse gases driving global warming and thus have a moral (and hopefully legal) responsibility to provide real leadership in trying to curb it – not just be at the same reduction targets as others. Scientists point out the technologically advanced societies like NY have the technological ability to move to 100% clean energy much faster than other states or nations. So we should do so.

NYS should evaluate how its climate change policies should be modified to reflect a target of no more than 1.5 degree. It should fund a scientific study of what steps NY should take to meet this new target, with input and direction from impacted communities. A goal of net zero carbon emissions by 2030 for instance seems more in line with the goal of 1.5 degrees

The 1.5°C marker pathway is defined as the most challenging mitigation pathway that can still be defended as being techno-economically achievable. Unfortunately, there is no guarantee that either pathway actually achieves the projected limits.

When Cuomo and Gore recently announced their support for the cap of 2 degrees (and a 80% reduction in greenhouse gases by 2050, based on 1990 levels), they sided with the industrial countries led by the US versus more than two-thirds of the others countries and thousands of civil society groups. (Note: Japan and the US this week pushed through a proposal banning civil groups from the pre-meeting in Bonn, and perhaps in Paris)

The 80 by 50 goal was adopted by NY in 2009 by Governor Patterson through an Executive Order, including the development and adoption of a Climate Action Plan. This Executive Order was renewed by Cuomo. A draft plan was developed but Cuomo has failed to finish it.

Christiana Figueres, executive secretary of the UN Framework Convention on Climate Change, recently told an audience of carbon traders: “Two degrees is not enough – we should be thinking of 1.5C. If we are not headed to 1.5 we are in big, big trouble.” (The Guardian)

Some prominent figures did sign a letter earlier this year by Lester Brown and others (Mark Ruffalo, Josh Fox) calling on Paris treaty to set a goal of net zero carbon emissions by 2025.

The Jacobson study in 2013 showed that it was technologically feasible for NY to get to 100% clean energy by 2030 – though subsequent versions have pushed the timeline back to 2050 to reflect political and economic barriers and opposition. But even that slower timeline still has NY getting to 85 to 90% renewable energy by 2030 – since it is the last few percentage points that are most difficult.

Limiting the average global surface temperature increase of 2°C (3.6°F) over the pre-industrial average has, since the 1990s, been commonly regarded as an adequate means of avoiding dangerous climate change, in science and policy making. However, recent science has shown that the weather, environmental and social impacts of 2°C rise are much greater than the earlier science indicated, and that impacts for a 1°C rise are now expected to be as great as those previously assumed for a 2°C rise

(From the New Republic) The difference in projected risks between 1.5 degrees Celsius and 2 degrees Celsius of warming is particularly important for highly temperature-sensitive systems, such as the polar regions, high mountains and the tropics, and low-lying coastal regions. At 2 degrees Celsius the very existence of some atoll nations is threatened by rising sea-levels. Limiting warming to 1.5 degrees Celsius may restrict sea level rise below one meter.

Yet even at 1.5 degrees Celsius warming, regional food security risks are significant. Africa is particularly vulnerable, with significant reduction in staple crop yields in some countries. Current levels of warming are already causing impacts that many people will not be able to adapt to—more scope for adaptation would exist at 1.5 degrees Celsius, especially in the agricultural sector.

Ten years ago prominent climate scientist James Hansen said the 2 degrees Celsius threshold “cannot be considered a responsible target” and subsequently called for a 1 degrees Celsius limit, with a carbon budget of just 500 Gt. Hansen told ABC breakfast radio that it was crazy to think of 2 degrees Celsius as a safe limit.

Hanson has called to commit to a 1°C danger limitor, with a 350 ppm CO2 target, which is lower than today’s 400 ppm. ‘[T]he oft-stated goal to keep global warming less than two degrees Celsius (3.6 degrees Fahrenheit) is a recipe for global disaster, not salvation.’ Others consider the 2°C target scientifically unfounded, due to insufficient data and reasoning. ( takes its name from Hanson’s target).

(From Science Daily) Limiting temperature rise by 2100 to less than 1.5°C is feasible, at least from a purely technological standpoint, according to the study published in the journal Nature Climate Change by researchers at the International Institute for Applied Systems Analysis (IIASA), the Potsdam Institute for Climate Impact Research (PIK), and others. This level is supported by more than 100 countries worldwide, including those most vulnerable to climate change, as a safer goal than the currently agreed international aim of 2 degrees Celsius.

Some do argue that setting a limit based on temperatures is not the correct approach. Instead, one should look at a carbon or greenhouse gas emission bubble. It will take just six years of current global emissions to exhaust a carbon budget that would give a good chance of keeping global warming below 1.5 degrees.

If there is anything close to consensus is that we should eliminate fossil fuels and transition to 100% renewables as fast as possible. And the sooner ones begins to sprint, the sooner one can get to the finish line. And to avoid the most catastrophic impacts of climate change we need to a technological, political and economic mobilization comparable to what the US did after the attack on Pearl Harbor.