Rebuttal

Too Cool

Bjorn Lomborg missed the mark in his attacks on a new report about the costs of climate change.

Contrary to alarming suggestions by Bjørn Lomborg in his article for Foreign Policy, DARA's recent Climate Vulnerability Monitor report is not a house of cards hinging on "one change in the model, namely including the impact from heat on labor productivity." Our report is a comprehensively updated assessment of the harm to human society and current economic development if we fail to act on climate change. It is anchored in latest mainly peer-reviewed studies and was developed in conjunction with detailed field research in Africa and Asia as well as successive review phases by more than 50 leading experts.

Lomborg asserts that the solutions the report promotes will be costly, but the whole point is to look at climate change through the lens of minimizing losses and maximizing gains in human, economic and environmental terms. As its title -- "A Guide to the Cold Calculus of a Hot Planet" -- suggests, the report is actually cold-minded good news, not "unfounded alarmism and panic." The costs of action may be "huge," but so are the benefits: We can deal with climate change, save millions of human lives, help slow rapid environmental degradation, rescue lagging progress on poverty reduction, and actually make money in the process.

The main difference between our study and earlier research comes from a revised treatment of the consequences of climate change versus its causes. The distinction helps to explain what is wrong with Lomborg's questioning of our estimations of costs and deaths due to climate change.

Most previous research of this kind has considered the impacts of climate change together with an effect called "carbon fertilization," meaning the stimulus of plant growth due to high atmospheric concentrations of carbon dioxide. CO2 is a natural ingredient in plant photosynthesis, and as its levels rise many scientists expect crop yields to improve in certain places.

The thing is, what we call "the climate" only means average weather. Climate change is simply a change in average weather. Crucially, atmospheric CO2 and carbon fertilization are not consequences or impacts of shifts in the weather. They relate instead to the causes of climate change. Failing to tackle climate change will lead to both temperature and CO2 rising in tandem. So it makes perfect sense to account for carbon fertilization when considering the future impacts of climate change, even when it is not one. In fact, on the basis of current research, we estimated that by 2030, carbon fertilization could be generating hundreds of billions of dollars in benefits every single year. For these reasons, prominent experts rightly consider carbon fertilization entirely relevant for the global warming debate.

But we make the case that many other effects that are similarly tied to the causes of climate change (but not weather-related) are of equal relevance to the global warming debate and have traditionally been overlooked.

Take the world's oceans for instance, which absorb one third of all CO2 released. Doing so makes them more acidic and harms marine life -- especially coral, molluscs, and shellfish that struggle to access key nutrients as water pH changes. This is not a weather-related impact, but it is an important cost to the fisheries sector. Another example worth considering is rising levels of ozone in smog at ground level that. Unlike CO2, smog is toxic for plant growth and triggers further losses.

Our simple suggestion is that either you take all relevant impacts tied to the causes of climate change into account, or you take none of them. Our report separates out both issues to enable independent examination. Is this deliberately misleading, as Lomborg suggests? No, it is clarification: Considering only carbon fertilization without other non-weather effects only distorts the true costs of climate change. It is one of the key reasons why many experts have concluded that overall climate change may not be much of a cost to the world economy in the decades ahead and it is a central pillar of the economic arguments for taking less action to address the problem, such as those espoused by Lomborg.

When the impacts of climate change (we simplify as "climate") and the effects linked to its causes (simplified as "carbon") are taken into account, we see that the economic costs are already severe. In fact, they  already dwarf the latest estimations of the costs of tackling climate change. Taking action, moreover, will minimize both climate and carbon losses going forwards.

This is not just an economic issue: CO2 might help plants, but air pollution leads to widespread illness and death -- pollution caused by the same fuels that are the mainstay of the world's current and projected energy systems. Despite Lomborg's assertion that air pollution is "almost entirely unrelated to global warming," burning fossil fuels is well understood as the chief source of climate-changing greenhouse gases. Less well known is that the burning of other types of fuels, such as wood and crop waste, also warms the planet. Their incomplete combustion in indoor cooking stoves -- also tremendously harmful for human health -- or field burning, generates soot and other pollutants that have been estimated as the second-greatest contributors (after CO2) to current global warming, because they absorb radiation and darken glaciers and snow.

Pollutants like soot don't stay in the air for very long, but when generated everyday they continuously warm the planet. The U.S. and Canadian governments together with others have made a priority of addressing them as a complement to tackling conventional gases like CO2. Such action has the potential to lessen the short-term increase in warming at low cost with important -- even immediate -- health, development, and environmental benefits. This is the impetus behind such promising new efforts as the Global Alliance for Clean Cookstoves.

Lomborg rightly points out that some of the journalists who covered the report misattributed our air pollution and other carbon economy death estimates to climate change. In accordance with findings of the actual public health community that differ from Lomborg's own views, global warming does indeed lead to large-scale mortality and illness. But mortality linked to the causes of climate change (not caused by it) are an order of magnitude greater in scale. Why should we ignore them?

Regardless, the mass mortality and illness outlined in our report are indeed contingent with climate change just like carbon fertilization is. If you reduce hazardous air pollution, it is difficult to not also reduce warming emissions. A world economy shifting to a more environmentally sound, safer, healthier, and lower carbon-intensity energy footing would progressively eliminate these health hazards, with some benefits reaped right away.

Returning to labor productivity, Lomborg himself edited a study in 2010 on the costs and benefits of climate change that recognized labor productivity as a potentially large unaccounted cost. Lomborg's own institution also publishes other work from one of the authors of the study we relied upon regarding labor. Relying on a single study for a single indicator is commonplace for this type of research -- supporting research is referred to in the explanatory texts of the report.

Labor productivity is the most significant of our 34 indicators, but substantially downgrading its scale would not alter our report's conclusions.

Deliberately adapting to climate-change impacts, including measures to reduce occupational heat stress, can be cost-effective, meaning less costly than if no actions are taken. Our estimated 2030 costs represent a scenario in which no serious deliberate action is taken, and could be lower if, unlike today, the situation is the reverse. But adapting is not always cheap: Expanding air conditioning as a response to indoor worker stress is highly costly and only generates more pollution, for instance. We actually have a separate indicator to measure the cost of simply maintaining, as the planet warms, similar comfort levels for indoor zones that are already climate controlled.

Spending billions of dollars a year painting cities white, as Lomborg suggested, will not make a dent in heat-driven labor productivity losses since the problem is of greatest concern for outdoor workers not in cities. Nor can farmers just displace work into the relatively cooler dark of night, because visibility also contributes to productivity.

Faced with the pervasive ramifications of a hotter planet, quick fixes like those touted by Lomborg would be about as effective as arranging deck chairs on the Titanic -- as one speaker at our report's launch noted.

Two decades without adequate action on climate change have already locked in many of the estimated impacts for 2030 outlined in our report, but addressing, correcting and acting on this knowledge will increase prosperity now. Why wait?

MICHAEL KAPPELER/AFP/Getty Images

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