Emerging scientific knowledge in anticipation of Durban’s COP17
AUTHOR: Richard Cicone, President, ISCIENCES, L.L.C.
As has been our practice since the 2009 United Nations Framework Convention on Climate Change (UNFCCC) Conference of the Parties (COP) at Copenhagen, we release Road to Durban , which provides a snapshot of events that have transpired since the last meeting, 2010’s COP16 in Cancun. We strive to provide an overview that makes it easy to digest what is going on in this prolonged, complex, and highly politicized process that started with the UNFCCC produced at the United Nations Conference on Environment and Development (UNCED) in Rio de Janiero (1992). This review, we hope, will provide those of you interested in humankind’s efforts to avoid what the UNFCCC refers to as“dangerous anthropogenic interference with the climate system” with a concise summary of key emerging science topics.
Image courtesy of Wikimedia Commons
Given what is at stake, progress has been painstakingly slow. The autonomous International Energy Agency (IAE) assesses that even with moderate “new policies” for mitigation, the world is on an emissions pathway that will lead to global average temperatures by the end of this century on the order of +3.5°C (+11°F) as compared to temperatures at the start of the 19th Century.(1) We now approach warming of +1°C as concentrations of carbon dioxide (currently the biggest culprit among the greenhouse gases) currently average more than 390ppm at monitoring stations worldwide(2). We also continue our assault on the world’s forests which, due to deforestation and fire, contribute about 12% of human emissions of CO2.
As we continue our seemingly slow but steady ascent to warmer temperatures, we replace incandescent light bulbs with fluorescent ones, buy a few more electric cars, and cross our fingers–but do little else to reduce greenhouse gas (GHG) emissions. The world community recognized GHGs would be an eventual threat to human security 29 years ago in Rio. Sixteen Conferences of the Parties later, we have an ineffective Kyoto Protocol, a nearly broken process of negotiation, and little else. Will this all change in South Africa at Durban just one month from now?
Recent developments in climate science could serve as the motivation COP17 delegates need to move forward in Durban. COP17 is the last gathering before the first commitment period of the Kyoto Protocol ends on December 31, 2012, with no binding instrument in place post-2012 to address climate change. Although differing viewpoints between developed and developing countries have hampered significant progress to date, recent scientific data about rising global temperatures, the role of forests in mitigating GHG emissions, and extreme weather patterns is sure to play a large role as nations determine which path to take. Let us look at some of these developments.
Projected changes in global temperature (graph courtesy of UNEP/GRID)
Limiting the Rise in Global Temperature
To date, the goal of current emissions reductions pledges has been to limit the increase of GHG emissions to +2°C. To reach this goal, GHG emissions should not exceed 450ppm (in CO2 equivalent units or CO2e) but according to the U.S. Department of Energy’s Energy Information Administration (EIA), the world’s projected emissions pathway is 650ppm. Scientists have determined that GHG concentration goals are useful targets, but cumulative anthropogenic emissions are a more important metric. A series of recent studies has established thatif we are to constrain temperatures to+2°C we must budget our use of fossil energy so that cumulative post-1750 emissions do not exceed one trillion tonnes of carbon. (3)
Unfortunately, we have already used about half of this quota over the last 200 years and at our current pace we will have consumed what is left by mid-century. With emissions from the developing world increasing and projected emissions from the power sector locked in, this goal is not achievable without draconian changes in policy including mandated reduction in use of fossil fuels, increased energy conservation and efficiency and increased green tech spending. In addition, global demand for oil, natural gas, and coal must peak before 2020. A transformation of this scope has never occurred, and it is unlikely that it will. Nations want to improve their economy and this improvement depends on energy; most energy comes from coal, oil, and natural gas. Renewable sources will not replace fossil sources fast enough, conservation measures that have little economic impact are scarce, and improving energy efficiency is unlikely to be at a pace to offset emissions sufficiently. Increasingly, scientists are acknowledging that limiting warming to +2°C will not be possible.
The realization that it will be impossible to limit global temperature rise to +2°C while adhering to current energy policies may facilitate cooperation and decrease deadlock among COP delegates as pressure to act intensifies, although the risk of finger-pointing and disagreement certainly exists. What will be the next goal? Some scientists believe the consequences of failing to adhere to+2°C will include “weather weirding” (4)–one meter sea level rise over this century and more thereafter, disruption of natural ecosystems, and threats to human health, water and food security. Can we exercise the discipline as a world community to limit warming to +3°C? This will occur as a result of atmospheric CO2e concentrations reaching 550 ppm. The DOE/EIA says we are on a 650 ppm emissions pathway if governments adopt new policies, and the EIA expresses concern that we may be on an emissions pathway beyond that. Much remains to be done.
Forests as Carbon Sinks
Image courtesy of Wikimedia Commons
The terrestrial flows of carbon between and within the oceans, Earth’s terrestrial surfaces, and the atmosphere have resulted in an apparent imbalance as atmospheric levels of carbon-based greenhouse gases continue to increase. Scientists have for some time referred to a “missing sink” – a large amount of carbon they knew was being sequestered somewhere on the terrestrial surface. This uncertainty lead to doubt about basic processes we needed to understand to help explain why so much carbon continued to be accumulated in theatmosphere. A recent study essentially identified the “missing sink” as intact tropical forests and confirmed that the world’s forests currently sequester 861 ± 66petagrams of carbon, while disturbed forests are net emitters of carbon.(5) Therefore, although the carbon budget is closed, the terrestrial surface is unfortunately still emitting more carbon into the atmosphere than it is sequestering as deforestation and burning practices overwhelm the forests’ inclination to absorb and sequester carbon. This finding has generated increased interest in the role forests play in sequestering increasing GHG emissions, with specific attention being paid to the increase or decrease in the size of sinks within individual nations. It also underlines the importance of preserving the world’s intact forest systems.
At COP 17, science on the key role of carbon sinks in mitigating GHG emissions may propel more funding for programs such as REDD+ and the Green Climate Fund as the importance of green land-use, such as carbon sinks grows. The spotlight is sure to shine upon the need for sustainable forest harvesting practices.
Extreme Weather: Daily Evidence of Climate Change
Floods in South Asia (image courtesy of Wikimedia Commons)
Long droughts, intense heat waves, monsoonal rains and heavy flooding are a few of the weather patterns currently observed on Earth. A recent Intergovernmental Panel on Climate Change (IPCC) draft report affirms a 2-in-3 probability that extreme weather has already worsened due to human-induced GHG emissions. IPCC scientists are 99% certain that the world will experience an increase in extremes of heat and decrease of cold. The frequency, duration, and intensity of extreme weather events will continue to increase over the coming decades. Scientists have also determined that the water holding capacity of the atmosphere increases at a rate of 7% for every 1°C increase in global average temperature. They estimate that this could result in increases in precipitation on the order of 2% for every 1°C increase.(6) However, this does not happen uniformly across the surface of Earth. They expect the subtropics to become drier, and the temperature regions of the earth’s terrestrial surface to become wetter. Ironically, in those regions the water will come in more intense and less frequent bursts due to the changes in the atmosphere’s water holding capacity, resulting in both increased flooding and increased droughts in temperate regions. We can indeed expect the weather to get “weirder.”
Emerging science on extreme weather patterns may intensify discussions on adaptation for the most vulnerable nations at COP17. In addition, developed nations may participate with a new sense of urgency as their vulnerabilities are also exposed.
Climate Sensitivity
Image courtesy of Wikimedia Commons
What makes us think that the climate is so sensitive to increases in concentrations of CO2? Repeatedly, climate models estimate that the most likely result of doubling atmospheric CO2 (all else being equal) is an increase of 3°C, and that it is more likely that the temperature will increase by as much as 4.5°C (vs. 2°C). This was true in 1979 when the U.S. National Academy of Sciences Charney Committee revealed its concern over climate change, and in most every IPCC report, in declarations of all national Academies of Science, and in myriads of scientific papers. (7) Still, the notion that climate is insensitive to changes in atmospheric concentrations of CO2 is a central argument held by those who disagree with the prevailing opinion of climate scientists. Aren’t climate models the fabrication of climate scientists who can jury-rig the results? Not likely, as historical evidence repeatedly points to the same conclusion. Paleoclimatologists literally dig deep – in ocean mud, old ice, and other records of the past such as tree rings – to determine how climate may have behaved through history in the presence of forces that affect the Earth’s radiative balance.(8) Recent paleoclimate science findings reinforce the idea that if a radiative forcing equivalent to doubling atmospheric concentrations of CO2 occurs, the climate tends to respond by changing average surface temperature by about 3°C. No suspect models–just the facts, as Jim Hanson recently declared.(9)
The UNFCCC representatives tend not to have problems with the notion of climate sensitivity. But those that feel the pressure to avoid what some think of as “dangerous interference with the economic system” are increasingly faced with the dilemma that our economic system may be facing greater threat from inaction. Positive actions to mitigate climate change may actually benefit the world’s economy. Indeed, IEA estimates in the 2011 World Energy Outlook that every dollar of mitigation saved now will generate four dollars in future costs. How this increasing realization will affect progress in Durban and beyond is a story worth watching.
Looking Ahead to Durban
As delegates at COP17 discuss and review nations’ commitment to matters such as emissions reductions and development and transfer of green technology, emerging science will serve to underline the urgency of making progress. To further explore how recent developments in climate change science may affect discussions in Durban, please see Kyoto and Beyond: Road to Durban, the fifth installment in ISciences’ ongoing series on multilateral agreements related to climate change.
(1) International Energy Agency World Energy Outlook, WEO 2011
(2) NOAA CO2 monitoring website
(3) Allen, Myles R et al. “Warming Caused by Cumulative Carbon Emissions Towards the Trillionth Tonne.” Nature 458.7242 (2009) : 1163-6.
(4) Thomas Friedman coined the term “weather weirding” in an effort to describe the weather we have all experienced in one form or other in the last few years. For a gallery of “weather weirding” pictures, please visit: http://www.guardian.co.uk/environment/gallery/2011/jun/28/2010-year-global-weirding
(5) Pan et al, “A Large and Persistent Carbon Sink in the World’s Forests,” Science 19 August 2011: vol. 333 no. 6045 pp. 988-993
(6) Stephens, Graeme L, and Yongxiang Hu. “Are Climate-related Changes to the Character of Global-mean Precipitation Predictable?” Environmental Research Letters 5.2 (2010) : 025209. Web. 11 July 2011
(7) Charney Report, 1979; IPCC AR4 Physical Science Basis, 2007, Solomon, 2011
(8) As the Laws of Thermodynamics demand, radiative imbalance is what ultimately alters the Earth’s climate as the system seeks a new equilibrium by warming or cooling as dictated by Plank’s Law
(9) James E. Hanson, Makiko Sato: Paleoclimate Implications for Human-Made Climate Change, 2011
Figure 2. Time series of global mean sea level (from 1980 – 1999 mean) in the past and as projected in the future. (Source: IPCC)
Figure 3. Ensemble temperature forecasts for a given point on the Earth. The black line indicates observed temperature over time, and the red lines indicate replicate CFS forecasts for 28 ensemble members. The background colors indicate temperature anomalies based on a 50 year climatology. Source: ISciences.
Figure 4. An example of how the globe is divided up into “voxels” (three dimensional pixels) to facilitate simulations. The processes shown in the inset are simulated in each square. Higher resolution models simulate smaller, more numerous voxels. Source: Wikimedia Commons
“ISciences is proud to sponsor Tech Twilight again this year,” said Michael Metzler, Vice President, adding, “we support the Ann Arbor Hands-On Museum and look forward to sharing our love of science with attendees of all ages.”
Figure 1. An example of a CFS precipitation forecast for August, 2010 (issued during the last week of July 2010). Red indicates drier than normal, blue indicates wetter than normal. Cross-hatching indicates uncertainty in the forecast. Source: NCEP/CPC (source data); ISciences (analysis).
The ten maps in the collection cover two different ranges of C02 increase. The maps are based on a study by J.W. Williams et al. published in the Proceedings of the National Academy of Science in 2007. The study looked at the results of multiple global change models run against two different scenarios and compared the anticipated climate conditions to current and historical ones. The analysis produced a global map showing standardized scalar index of climate dissimilarity (SED) between the end of the 20th and the end of the 21st centuries. The closer the SED value, the more similar the pixels. The key findings were 1) that by 2100 substantial proportions of the Earth’s land surface will be “novel” climates – conditions that have not been experienced in the past – and 2) that currently existing climates will “disappear” from substantial portions of the Earth’s surface. The PNAS article has been quite influential, with at least 190 citations in scholarly journals since 2007.