Gary Yohe

Wesleyan University · Department of Economics

Strenuous, prompt emissions control efforts are needed to avoid serious climate related damage. This effort can be taken at manageable cost to the economy, though polices need to help correct a likely uneven burden of the cost.

In 1995 IPCC could only report that the evidence suggests a “discernible human influence” on the climate. In its latest assessment, IPCC declared that the evidence was “unequivocal”. This essay explores how this happened.

The new Biden Administration and Congress face a deadline for acting to reverse actions at the “eleventh-hour” by the previous Administration.

In his book, Unsettled, Steven Koonin deploys that highly misleading adjective to falsely suggest that we don’t understand the risks well enough to take action against climate risk. In fact, nations design and implement actions that manage risk in all sorts of incompletely understood circumstances.

The global response to the climate threat requires a joint effort among nations in climate science and policy analysis. Geopolitical forces are making it difficult to sustain the needed collaboration.

With a narrowly split House and Senate passing legislative climate proposals will be difficult. Fortunately, President Biden’s executive orders and other presidential actions enjoy benefits of going with, not against, a demonstrable tide of public.

The prospects for climate action will be influenced by the credibility of its treatment in political debate. It will be important to be clear about both risks and opportunities, recognize the distribution of cost, and preserve room for needed bipartisan action.

With COVID-19, as with climate, model-based counterfactual experiments are used to explore a variety of possible futures in order to inform policy. “What will likely happen if we did this?” or “What will likely happen if we did not do that?” are the two critical questions that need to be confronted. Criticism of the procedure is misplaced.

Scientific studies of how the planet works make it clear that human activity—in particular the combustion of fossil fuels—is the main cause of the observed increase in global temperature in the industrial age. It is a conclusion long expected and confirmed by research conducted in many nations.

The U.S. public largely accepts that climate change is real, human caused and serious—yet concern with the issue does not rise to a high enough priority to command political action. Greater effort is needed not only to explain the risk of inaction on climate but also to better understand the public response to the information that is available.

Protection of the U.S. from climate damage depends on the success of the international climate regime, which is influenced by the action of the agreement’s richest nation. So it is in the U.S. national interest not only to cut its emissions but also to provide aid to other nations.

TV debates in advance of a presidential election offer an opportunity to expose the candidates’ views on climate. Here is an effort to suggest questions that debate moderators might use.

As world leaders confronting the energy consequences of the Russian invasion of Ukraine face a binary choice between two strategies: rejuvenate investment in fossil fuels or accelerate investment in a transformation to alternative sources. The later enjoys the collateral benefit of strengthening democracies around the world.

The Trump decision to leave the Paris Agreement showed a serious underappreciation of the impact on efforts of other nations. Affected as the nation is by the global response, it is in the U.S. interest not only to reduce domestic emissions but also to aid less wealthy countries.

Progressives in the Congress incorporated programs to fight climate change in an ambitious plan to meet a host of societal objectives. Merging policy domains in this way risks a loss of focus on the climate threat.

In the United States, decades of climate policy have been like a house of cards, easy to begin building, but difficult to expand and maintain. We need to build a better, stronger house. Our kids will be living in it for a long time to come.

For decisions born of the appropriate iterative risk management approach to climate change, recurring and troubling pattern of “first-time” historic weather events can provide firm support for citizens and leaders to acknowledge human causation and call for needed mitigation and adaptation steps.

Public support for climate action will be driven in one of two ways: by understanding the risk in advance or in experiencing the damage when the possibility of an effective response is much reduced. Increased effort is needed to convince the public of the cost of delay.

A carbon tax is a powerful if underutilized way to control carbon emissions. It has the additional advantage of producing a ‘carbon dividend’ that can be used to moderate the distributional consequences of the policy’.

Climate at a particular location is the average of the weather over a 20 or 30 year time frame. Climate warming is expected to yield extreme weather events at odds with that historical record, and the rising likelihood of extremes in recent years can be attributed to this ongoing change.

In the United States, decades of climate policy have been like a house of cards, easy to begin building, but difficult to expand and maintain. We need to build a better, stronger house. Our kids will be living in it for a long time to come.

As evidenced by increases in the intensity and frequency of extreme events, the risks associated with climate change are getting worse. They are getting harder to predict because the ranges of historical data are no longer descriptive of the exaggerated uncertainty that marks the current climate, not to mention any view of what the future might hol...

The word “existential” is applied freely to attract attention to the risks posed by climate change and the coronavirus pandemic. Their usage is problematic in the absence of a specification of intended scope.

Bringing the now widely accepted iterative risk management approach to the next National Climate Assessment would be an important step for the incoming Biden Administration as it tries to communicate the need for climate action to the country.

The Biden Administration’s emphasis on equity in policy making faces challenges in the the current political climate. Overcoming these barriers is a critical component of any effective climate change action strategy.

The social cost of carbon is the estimated present value cost of damages from current and future climate change. It is extremely sensitive to the geographic scale of the calculations and the degree to which future effects should be discounted. As a result, it is very vulnerable to manipulation for political gain.

Paralysis and despair may arise if exceeding a 1.5°C target is believed to signal climate Armageddon. This response would imperil the continued energy and attention needed to sustain the global effort to cut greenhouse emissions, and such ambitious targets must be employed with care.

There is a two-way interaction between COVID risk and climate risk. The response options to climate-driven extreme events exacerbates exposure to infectious disease. Also, the climate-related damage likely increased the animal-to-human transmission of disease.

In one of his earliest actions President Biden sent a letter directing the head of the Office of Science and Technology Policy to prepare plans to restore the public’s faith in the value of science and guide its application to national needs. It was similar to action in 1944 by President Roosevelt, though under very different political conditions.

Humanity knows from experience it cannot protect itself from all of the hazards that plague the world. It follows that abatement and adaptation cannot be perfect. There will always be residual damage, and so can only choose how much suffering it wants to try to avoid.

The COVID-19 pandemic held the promise of restoring faith in science and underscoring the value of precautionary action. It also exposed uneven distributions across the social, economic, and political determinants of our ability to respond to climate change. These revelations have, however, not lead to more efficacious actions to abate or adapt to...

One consequence of a warming planet is an increase in climate-related events, each of which causes billions of dollars in damage. The disasters to date are only a taste of what is to come if society does not cut greenhouse gas emissions.

Concurrent extreme events, each enhanced by climate change, can combine to produce an enhanced disruption. They have been found to cause catastrophic economic and environmental damage far greater than any one factor alone.

Despite the fact that we live on a “noisy” planet there is a compelling case for global warming, based on temperature records over hundreds of years and analysis by scientists in many nations. It is evidence that the public largely accepts.

Anyone interested enough to crack open this book is no doubt aware of the seriousness of the climate threat, and that action by the U.S. is essential to any global solution. There is no international police agency to enforce the needed reduction in greenhouse gas emissions. The global agreement to meet the climate threat, embodied in the Paris Agre...

Modeling is a critical part of crafting adaptive and mitigative responses to existential threats like the COVID-19 coronavirus and climate change. The United Nations, in its efforts to promote 17 Sustainable Development Goals, has recognized both sources of risk as cross-cutting themes in part because both expose the wide list of social and economi...

Journalists, moderators, and the public have an important opportunity to question the presidential and vice presidential candidates in the upcoming TV debates.

The text and associated Supplemental Materials contribute internally consistent and therefore entirely comparable regional, temporal, and sectoral risk profiles to a growing literature on regional economic vulnerability to climate change. A large collection of maps populated with graphs of Monte-Carlo simulation results support a communication devi...

Recent advancements in the availability of models and data to characterize the economic impacts of climate change have improved our ability to project both the physical impacts and economic effects of climate change across economic sectors of the United States. These advancements have in turn provided an opportunity to estimate these impacts across...

This handbook is currently in development, with individual articles publishing online in advance of print publication. At this time, we cannot add information about unpublished articles in this handbook, however the table of contents will continue to grow as additional articles pass through the review process and are added to the site. Please note...

As states, cities, tribes, and private interests cope with climate damages and seek to increase preparedness and resilience, they will need to navigate myriad choices and options available to them. Making these choices in ways that identify pathways for climate action that support their development objectives will require constructive public dialog...

Full- text available through the IPCC website: https://www.ipcc.ch/sr15/

Trajectories of policy-driven transient temperatures are reported here for four different maximum temperature targets through 2100 and a “no-policy” baseline because it is they, and their associated manifestations in other impact and risk dimensions, that natural and human and natural systems see in real time as their common future unfolds. It foll...

The reasons for concern framework communicates scientific understanding about risks in relation to varying levels of climate change. The framework, now a cornerstone of the IPCC assessments, aggregates global risks into five categories as a function of global mean temperature change. We review the framework's conceptual basis and the risk judgments...

Uneven patterns in the rate of climate change have profound implications for adaptation. Assuming a linear or monotonic increase in global or regional temperatures can lead to inefficient planning processes that underestimate the magnitude, pattern, and timing of the risks faced by human and natural systems, which could exaggerate future impacts an...

Resilience has moved from being a peripheral ecological concept to a central goal, in the development discourse. While the concept has become popular, operationalizing resilience has been difficult. Many frameworks have been proposed to operationalize resilience but no common framework has been agreed upon. The present article demonstrates a step b...

There are two sides to the economics of climate change - the economics of the economic damages, risks, and opportunities associated with the impacts of climate and the economics of the benefits and costs of mitigation. The benefits of mitigation are generally estimated as net damages that can be avoided or delayed by actions designed to reduce emis...

The Setting This chapter describes the information basis for the Fifth Assessment Report (AR5) of IPCC Working Group II (WGII) and the rationale for its structure. As the starting point of WGII AR5, the chapter begins with an analysis of how the literature for the assessment has developed through time and proceeds with an overview of how the framin...

Introduction This chapter synthesizes the scientific literature on the detection and attribution of observed changes in natural and human systems in response to observed recent climate change. For policy makers and the public, detection and attribution of observed impacts will be a key element to determine the necessity and degree of mitigation and...

Working Group II of the Intergovernmental Panel on Climate Change (IPCC 2007a) focused their attention on adaptation and vulnerability in their contribution to the IPCC's Fourth Assessment Report. Societies notice many of the impacts of climate change by detecting increasingly intense and/or more frequent extreme weather events and attributing the...

Increases in the frequency and intensity of some climate extremes—especially heat waves, coastal flooding, and inland precipitation--are projected to challenge the Northeast’s environmental, social, and economic systems. This will increase the vulnerability of residents, especially its most disadvantaged populations. Vital infrastructure will be in...

Human interference with the climate system is occurring. [WGI AR5 2.2, 6.3, 10.3-6, 10.9] Climate change poses risks for human and natural systems (Figure TS.1). The assessment of impacts, adaptation, and vulnerability in the Working Group II contribution to the IPCC’s Fifth Assessment Report (WGII AR5) evaluates how patterns of risks and potential...

science and assessment sometimes focus too strongly on avoiding false-positive errors, when false-negative errors may be just as important. In final form 5 January 2014 ©2014 American Meteorological Society T he concept of risk has been identified as a fundamental framing to the analysis of what to do about anthropogenic climate change, unani-mousl...

Climate change will generally increase the risk of negative consequences to forests and associated biosocial systems. Risk management identifies risks, estimating their probability of occurrence and magnitude of impact. A risk framework provides a means to quantify what is known, identify where uncertainties exist, and help resource managers develo...

Anthropogenic climate change has triggered impacts on natural and human systems world-wide, yet the formal scientific method of detection and attribution has been only insufficiently described. Detection and attribution of impacts of climate change is a fundamentally cross-disciplinary issue, involving concepts, terms, and standards spanning the va...

Among terrestrial environments, forests are not only the largest long-term sink of atmospheric carbon (C), but are also susceptible to global change themselves, with potential consequences including alterations of C cycles and potential C emission. To inform global change risk assessment of forest C across large spatial/temporal scales, this study...

Mitigation policies have traditionally been evaluated from the perspective of first-best worlds that have perfect foresight and full and immediate policy implementation. Adaptation assessments typically consider second-best worlds that incorporate the realities of market imperfections, institutional and informational constraints, delayed policy imp...

The selection of climate policies should be an exercise in risk management reflecting the many relevant sources of uncertainty. Studies of climate change and its impacts rarely yield consensus on the distribution of exposure, vulnerability, or possible outcomes. Hence policy analysis cannot effectively evaluate alternatives using standard approache...

We present an approach to assess and compare risk from climate change among multiple species through a risk matrix, in which managers can quickly prioritize for species that need to have strategies developed, evaluated further, or watched. We base the matrix upon earlier work towards the National Climate Assessment for potential damage to infrastru...

This postscript highlights questions that are particularly germane for thinking about how to use modern, state of the art investigations of impacts, adaptation, and vulnerability to advance a broader decision-supporting research agenda. They are drawn from the fundamental conclusion from the Fourth Assessment Report of the Intergovernmental Panel o...

This paper offers some thoughts on the value added of new economic estimates of climate change damages. We begin with a warning to beware of analyses that are so narrow that they miss a good deal of the important economic ramifications of the full suite of manifestations of climate change. Our second set of comments focuses attention on one of the...

The inability to verify nations' reported progress towards emission-reduction commitments is a stumbling block in climate change negotiations. Narrowing uncertainties in the global carbon cycle could help overcome this obstacle.

While current rates of sea level rise and associated coastal flooding in the New York City region appear to be manageable by stakeholders responsible for communications, energy, transportation, and water infrastructure, projections for sea level rise and associated flooding in the future, especially those associated with rapid icemelt of the Greenl...

At the request of Congress, the National Academy of Sciences convened a series of coordinated activities to provide advice on actions and strategies that the nation can take to respond to climate change. As part of this suite of activities, this study assessed, this study assessed how the nation can begin to adapt to the impacts of climate change....

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