Intergovernmental Panel On Climate Change Report Research Articles

Another exchange on climate change

Another exchange on climate change

Effective communication of uncertainty in the IPCC reports

The Intergovernmental Panel on Climate Change (IPCC) publishes periodical assessment reports informing policymakers and the public on issues relevant to the understanding of human induced climate change. The IPCC uses a set of 7 verbal descriptions of uncertainty, such as unlikely and very likely to convey the underlying imprecision of its forecasts and conclusions. We report results of an experiment comparing the effectiveness of communication using these words and their numerical counterparts. We show that the public consistently misinterprets the probabilistic statements in the IPCC report in a regressive fashion, and that there are large individual differences in the interpretation of these statements, which are associated with the respondents’ ideology and their views and beliefs about climate change issues. Most importantly our results suggest that using a dual (verbal—numerical) scale would be superior to the current mode of communication as it (a) increases the level of differentiation between the various terms, (b) increases the consistency of interpretation of these terms, and (c) increases the level of consistency with the IPCC guidelines. Most importantly, these positive effects are independent of the respondents’ ideological and environmental views.

COSP: Satellite simulation software for model assessment

Errors in the simulation of clouds in general circulation models (GCMs) remain a long-standing issue in climate projections, as discussed in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. This highlights the need for developing new analysis techniques to improve our knowledge of the physical processes at the root of these errors. The Cloud Feedback Model Intercomparison Project (CFMIP) pursues this objective, and under that framework the CFMIP Observation Simulator Package (COSP) has been developed. COSP is a flexible software tool that enables the simulation of several satellite-borne active and passive sensor observations from model variables. The flexibility of COSP and a common interface for all sensors facilitates its use in any type of numerical model, from high-resolution cloud-resolving models to the coarser-resolution GCMs assessed by the IPCC, and the scales in between used in weather forecast and regional models. The diversity of model parameterization techniques makes the comparison between model and observations difficult, as some parameterized variables (e.g., cloud fraction) do not have the same meaning in all models. The approach followed in COSP permits models to be evaluated against observations and compared against each other in a more consistent manner. This permits a more detailed diagnosis of the physical processes that govern the behavior of clouds and precipitation in numerical models. The World Climate Research Programme (WCRP) Working Group on Coupled Modelling has recommended the use of COSP in a subset of climate experiments that will be assessed by the next IPCC report. In this article we describe COSP, present some results from its application to numerical models, and discuss future work that will expand its capabilities.

The climate crisis: An introductory guide to climate change

Human‐induced climate change, sometimes called “global warming,” has, unfortunately, become a “hot” topic, embroiled in controversy, misinformation, and claims and counterclaims. It should not be this way, because there are many scientific facts that provide solid information on which to base policy. There is a very strong observational, theoretical, and modeling base in physical science that underpins current understanding of what has happened to Earth's climate and why and what the prospects are for the future under certain assumptions. Moreover, these changes have impacts, which are apt to grow, on the environment and human society. To avoid or reduce these impacts and the economic and human effects of undesirable future climate change requires actions that are strongly opposed by those with vested interests in the status quo, some of whom have funded misinformation campaigns that have successfully confused the public and some politicians, leading to paralysis in political action. Without mitigation of climate change, one would suppose that at least society would plan sensibly for the changes already happening and projected, but such future adaptation plans are also largely in limbo. The implication is that we will suffer the consequences. All of these aspects are addressed in this informative and attractive book, which is written for a fairly general but technically informed audience. The book is strongly based upon the 2007 Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) and therefore has a solid scientific basis. Many figures, graphs, and maps come from the three IPCC working group reports, although the captions often do not explain the detail shown. Given that the IPCC reports totaled nearly 3000 pages, to distill the complex material down to 249 pages is no mean task, and the authors have succeeded quite well.

Research Spotlight: New emissions scenarios say 2°C warming may be unavoidable

When it comes to modeling climate change, researchers rely on the specification of plausible emissions scenarios to explore how climate will change over the coming century. Using a standardized set of carbon dioxide and other greenhouse gas scenarios, researchers from different modeling centers can compare results and more methodically assess uncertainty in the Intergovernmental Panel on Climate Change (IPCC) reports. The emissions scenarios used in the past two IPCC reports were published in 2001 and need to be updated to take into account more recent socioeconomic modeling results. In a new study, Arora et al. use a completely new set of scenarios, referred to as representative concentration pathways (RCPs). These will form the basis for new climate projections to be assessed in the IPCC's Fifth Assessment Report (due out in 2014). Using an upgraded Earth system model—which takes into account carbon dioxide and other greenhouse gases, aerosols, land use change, and the flow of carbon between the atmosphere and the underlying ocean and land surface—the researchers are able to calculate the carbon dioxide emissions compatible with each RCP and, in particular, the emissions reductions required to meet certain levels of global warming. (Geophysical Research Letters, doi:10.1029/2010GL046270, 2011)

Communicating Uncertainty about Climate Change: The Scientists’ Dilemma

Communicating Uncertainty about Climate Change: The Scientists’ Dilemma

Skill and uncertainty in climate models

AbstractAnalyses of skill are widely used for assessing weather predictions, but the time scale and lack of validation data mean that it is not generally possible to investigate the predictive skill of today's climate models on the multidecadal time scale. The predictions made with early climate models can, however, be analyzed, and here we show that one such forecast did have skill. It seems reasonable to expect that predictions based on today's more advanced models will be at least as skillful. In general, assessments of predictions based on today's climate models should use Bayesian methods, in which the inevitable subjective decisions are made explicit. For the AR4, the Intergovernmental Panel on Climate Change (IPCC) recommended the Bayesian paradigm for making estimates of uncertainty and probabilistic statements, and here we analyze the way in which uncertainty was actually addressed in the report. Analysis of the ensemble of general circulation models (GCMs) used in the last IPCC report suggests there is little evidence to support the popular notion that the multimodel ensemble is underdispersive, which would imply that the spread of the ensemble may be a reasonable starting point for estimating uncertainty. It is important that the field of uncertainty estimation is developed in order that the best use is made of current scientific knowledge in making predictions of future climate. At the same time, it is only by better understanding the processes and inclusion of these processes in the models, the best estimates of future climate will be closer to the truth. Copyright © 2010 John Wiley & Sons, Ltd.This article is categorized under: Climate Models and Modeling > Knowledge Generation with Models

Environmental Reviews & Case Studies: Keeping below the Tipping Point: A Literature Review of Climate Change with Attention to NEPA

The courts are increasingly finding that National Environmental Policy Act (NEPA) documents need to address climate change impacts—both the impact of the project on climate change and the impacts of climate change on the project. In the scientific arena, the year 2007 was pivotal in climate change because the Fourth Assessment Report of the United Nations Intergovernmental Panel on Climate Change (IPCC) was issued. The IPCC report concluded that warming of the climate system is unequivocal and that this warming is primarily caused by increases in greenhouse gas concentrations. To address the issue and its impacts on a given project, policy, or program for a NEPA review, the analyst is presented with the difficulty of summarizing a massive amount of literature from the earth, biological, and physical sciences. This article provides a summary of the recent literature, addressing the IPCC report, the evidence for climate change, effects in different regions, NEPA implications, and mitigation strategies. NEPA reviews in the area of infrastructure in coastal regions and in the area of water supply will need special attention in light of climate change. All of this will make for much decision making under uncertainty, but ultimately NEPA documents and environmental decisions are likely to benefit from consideration of climate change because more resilient projects are likely to be approved, even if climate change is not as intense as some estimates. This article emphasizes NEPA-relevant events and is not intended to provide details on the current regulatory framework under other laws.

遠藤小太郎ほか論文「極地の氷の融解と海面水位変動に見る環境情報の伝達問題」の中の誤解について

Endo et al. says that the sea level will be lower due to the ice in the polar region, and refers to the IPCC (Inter-governmental Panel on Climate Change) assessment reports as if these reports would have supported the notion. The referred sections of IPCC reports, however, describe the effects of “polar ice sheets” of Antarctica and Greenland combined, and not “ice in the polar region” as Endo et al. says. The misinterpretations of these terms also lead to their unfounded and untenable criticism on the “White Paper on the Environment” published by the Ministry of the Environment, Japan.

A Culture of Neglect: Climate Discourse and Disabled People

A Culture of Neglect: Climate Discourse and Disabled People

Methane and nitrous oxide emissions from the ocean: A reassessment using basin‐wide observations in the Atlantic

We measured the concentrations of nitrous oxide (N2O) and methane (CH4) in the marine boundary layer and surface waters of the Atlantic Ocean from ∼50°N to ∼50°S during the Atlantic Meridional Transect expedition (AMT‐7) in 1998. The cruise track transects a variety of meteorological and oceanographic regimes. Unusually high mixing ratios of atmospheric CH4 were observed in the extratropical Northern Hemisphere, coinciding with globally high levels of CH4 associated with the El Niño event of 1998. Atmospheric N2O remained nearly invariable during the expedition, with only a small hemispheric difference (0.82 ppb). Throughout the cruise, these gases were saturated or supersaturated in the water. The coastal region was observed to be a significant source of CH4, while upwelling regions acted as strong N2O emission sources. We estimated the global oceanic emission of CH4 to be 0.6–1.2 Tg a−1, comparable to previous estimates from basin‐wide observations. However, our estimate turns out to be ∼10 times lower than the value in the 1990 to 2007 Intergovernmental Panel on Climate Change (IPCC) reports, which essentially all relied on the estimate by Ehhalt (1974). A bias toward high CH4 saturation anomalies is probably responsible for the overestimation of the marine CH4 source in the IPCC reports. The CH4 saturation anomaly in the ocean appears to have remained constant over an interval of 20 years in spite of the increase of atmospheric CH4, suggesting that the increase of the surface water temperature driven by global warming may be a major factor. Meanwhile, the N2O emission from the ocean, estimated in the present study to be 0.9–1.7 Tg N a−1, is ∼3 times lower than the value in the recent IPCC report [Denman et al., 2007], implying either weak upwelling activity or low amounts of dissolved N2O in upwelling subsurface waters, or both, in the Atlantic.

Runaway Climate Change: A Justice‐Based Case for Precautions

Runaway Climate Change: A Justice‐Based Case for Precautions

Taking the reins of the white horse of climate change

> Why human health and equity must become the central goals of climate change policy at the United Nations Framework Convention on Climate Change (UNFCCC) in December 2009. Until recently,...

Climate change, direct heat exposure, health and well-being in low and middle-income countries

Climate change, direct heat exposure, health and well-being in low and middle-income countries

Improving Communication of Uncertainty in the Reports of the Intergovernmental Panel on Climate Change

The Intergovernmental Panel on Climate Change (IPCC) assesses information relevant to the understanding of climate change and explores options for adaptation and mitigation. The IPCC reports communicate uncertainty by using a set of probability terms accompanied by global interpretational guidelines. The judgment literature indicates that there are large differences in the way people understand such phrases, and that their use may lead to confusion and errors in communication. We conducted an experiment in which subjects read sentences from the 2007 IPCC report and assigned numerical values to the probability terms. The respondents' judgments deviated significantly from the IPCC guidelines, even when the respondents had access to these guidelines. These results suggest that the method used by the IPCC is likely to convey levels of imprecision that are too high. We propose an alternative form of communicating uncertainty, illustrate its effectiveness, and suggest several additional ways to improve the communication of uncertainty.

Meeting the challenge of aviation emissions: an aircraft industry perspective

In 1999 the Intergovernmental Panel on Climate Change (IPCC) produced a report on aviation and the atmosphere that highlighted the role that aviation plays in climate change. As the report showed aviation impacts the atmosphere in a number of ways, including emissions of CO2 and NO x , water vapour and creation of cirrus plus contrails. Of these the significant climate impact comes chiefly from CO2, NO x and contrails/cirrus. In the years since the IPCC report green lobby groups, other NGOs and parts of the media have highlighted and foregrounded the role of aviation in climate change and have mounted a significant public relations campaign against the aviation industry. This paper acknowledges the role of aviation emissions in climate change and outlines how a number of stakeholders, especially the manufacturers of large civil aircraft, are seeking to create a cleaner and greener aviation system. The paper seeks to outline what might be realistically achieved through the current R&D drive for more efficient aircraft and some of the other non-technical initiatives that are underway. The author argues that generally the sector has been quite open in acknowledging its responsibilities on the climate change issue and is investing heavily in finding solutions on a range of fronts. The paper also contends that while aviation must shoulder its environmental responsibilities, governments should not embark on policies that will damage a highly successful sector that supports millions of jobs in the European Union.

Wissenschaftliche und politische Gründe für den Wandel der IPCC-Szenarien

Since its establishment, the Intergovernmental Panel on Climate Change (IPCC) has published three series of emission scenarios that represent the backbone of climate projections. The first IPCC series in 1990 proposed a single business-as-usual emission scenario as a reference, and three intervention scenarios. The third series of scenarios, published in 2000, which is used in the IPCC's recent Fourth Assessment Report, does not include any intervention scenarios but consists of six different reference scenarios. To assess the reasons for these changes, we analyze the changing structure of the IPCC scenarios and the intergovernmental review process they went through. We also compare the scenarios with scenarios from literature. We find that scientific reasons alone cannot explain these changes. During the unification process for the relevant IPCC report, the government representatives involved increased the number of reference scenarios, excluded intervention scenarios, and prevented scenario names that emphasized the interventionist character of those scenarios with low emissions. These findings illustrate difficulties in scenario construction that need to be resolved for the next generation of IPCC scenarios.

Teaching and Learning Guide for: The Geopolitics of Climate Change

Climate change is a security problem in as much as the kinds of environmental changes that may result pose risks to peace and development. However, responsibilities for the causes of climate change, vulnerability to its effects, and capacity to solve the problem, are not equally distributed between countries, classes and cultures. There is no uniformity in the geopolitics of climate change, and this impedes solutions.

Emission scenarios in the face of fossil-fuel peaking

Emissions scenarios used by the Intergovernmental Panel on Climate Change (IPCC) are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. We propose in this paper that it is useful to look at a qualitative model of the energy system, backed by data from short- and medium-term trends, to gain a sense of carbon emission bounds. Here we look at what may be considered a lower bound for 21st century emissions given two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by “peak oil” adherents, and second, that no climate mitigation policies are put in place to limit emissions. If resources, and more importantly, extraction rates, of fossil fuels are more limited than posited in full energy-system models, a supply-driven emissions scenario results; however, we show that even in this “peak fossil-fuel” limit, carbon emissions are high enough to surpass 550 ppm or 2 °C climate protection guardrails. Some indicators are presented that the scenario presented here should not be disregarded, and comparisons are made to the outputs of emission scenarios used for the IPCC reports.

Climate Change, Limits to Growth, and the Imperative for Socialism

The 2007 assessment report by the United Nations Intergovernmental Panel on Climate Change (IPCC) confirms that it is virtually certain that human activities (mainly through the use of fossil fuels and land development) have been responsible for the global warming that has taken place since the industrial revolution. Under current economic and social trends, the world is on a path to unprecedented ecological catastrophes. 1 As the IPCC report was being released, new evidence emerged suggesting that climate change is taking place at a much faster pace and the potential consequences are likely to be far more dreadful than is suggested by the IPCC reportThis article can also be found at the Monthly Review website, where most recent articles are published in full.Click here to purchase a PDF version of this article at the Monthly Review website.