How could the UN climate talks in Paris next month ratchet up the national plans (INDCs) and succeed in limiting global warming? Drew Jones of Climate Interactive presents scenarios from the C-ROADS simulation and explores how far these contributions get us, and what more is needed to keep warming to within 2° Celsius (3.6°F) of temperature change above pre-industrial levels.
The analysis comes from the Climate Scoreboard Climate Interactive has released, using the peer-reviewed freely available C-ROADS climate policy simulator developed in partnership with the MIT Sloan School of Management. Sir Robert Watson, former chair of the IPCC, led the external review of C-ROADS, which asserted that it was rigorously designed and suitable for widespread use.
Video Credits
Script and scenario design: Drew Jones and Climate Interactive staff. Production, edits, and graphics animation: Robert Klein, Klein Digital. Simulation scenario creation: Lori Siegel. Direction: Dayna Reggero. Filming and lighting: Peter Brezny. Our funders.
Inquiries: info@climateinteractive.org
Thanks for the clear and open access approach.
I may have misunderstood something, but looking at the 2°C curve I couldn’t see how the cumulative emissions fit with the 50% chance of 2°C carbon budget from the Synthesis report.
Checking the accompanying excel sheet the CO2e emissions from 2011 to 2100 for the 2°C pathway totalled 2789GtCO2e. With a very simple assumption that 20% of this relates to non-CO2 emissions, the remaining CO2-only budget for 2011 to 2100 is ~2231Gt.
The synthesis report’s headline CO2-only budget (for 2011-2100) for a 50% chance of 2°C is 1300GtCO2; (range of 1150 -1400Gt). Even for a lower chance of 2°C (~33% of not exceeding; or ~67% of exceeding) the headline budget is 1500Gt (range 1150-2050).
Consequently, I can’t reconcile the CO2-only budget of your 2°C pathway with the CO2-only budgets (headline and range) from Synthesis report. This is the case for both 50% and 67% of exceeding 2°C.
Am I missing something significant?
Many thanks in advance for any pointers you can offer to explain this difference.
Kind regards
Kevin Anderson
Univeristy of Manchester
Tyndall Centre
Kevin — Thanks for your good questions. And we particularly appreciate your digging into the numbers to this level. As you can imagine, there are many considerations when comparing output across studies, for example, the role of LULUCF, other gases, the start/stop year of accumulating emissions, and probabilities of achieving various temperature goals. So we are reviewing the data from the Synthesis report now and will post an answer to your question when we are sure we are comparing “apples to apples.” — Drew Jones
Great summary of the current state of play, thanks guys !
Is #COP21 a stepping stone to a safe climate? Or another brick in the wall of collective delusion that seeks hope in hopelessly weak goals and hopelessly weak actions? I’d be grateful for your group’s expert opinion of David Wasdell’s work on earth system sensitivity, showing that we have a negative carbon budget for 2C. http://www.apollo-gaia.org/harsh-realities-of-now.html
Your assumptions are predicated on climate response models that are overly conservative. The rate of warming as measured by ocean heat content changes over the last 4 years shows that we have DOUBLED the top-of-atmosphere energy imbalance from 0.6 watts per meter squared to 1.1 watts per meter squared in the last 7 years. The lapse rate and water vapor feedbacks respond slowly (10 years to reach full feedback) to a pulse of GHG emissions. Therefore we are currently operating on 2008 (or so) atmospheric abundance levels. Aerosol emissions associated with fossil fuels are masking approximately 1/2 of the total energy imbalance experienced by planet earth. Any aggressive emissions reductions will necessarily reduce aerosol emissions and the locked in warming at current GHG abundance levels will push the Earth above 2.0 C in the next 25 years.
In addition, forest biomas declines, tropical peat fires (see Indonesia) boreal forest and peat declines and the rapid increase of permafrost disassociation will ensure that even if we reduce anthropogenic GHG emissions to the levels you state, we will still have a strong likelyhood of reaching 4C by 2070. It should also be noted here that approximately 20% of the total earth energy imbalance results from the albedo change of a melting polar ice cap. This will reach ice-free conditions sometime around September of 2022.
We must do much more than these COP21 goals state. Only by removing billions of tonnes of CO2 from the earth’s atmosphere and reducing CO2 abundance below 350 PPMv will we allow for a dystopian future for our children, (as opposed to no future whatsoever).
P.S. we are currently at 1.1C above pre-industrial temperatures.
Does your study take into account increased methane releases from the artic as temperatures warm?
Also does your study take into account the westernisation of the developing worlds diet and the extra carbon producing all that extra meat and dairy will take?
Many thanks