Cool It: The Skeptical Environmentalist's Guide to Global Warming

Overview
"Cool It: The Skeptical Environmentalist's Guide to Global Warming" presents a contrarian, cost-focused assessment of climate change policy. Bjørn Lomborg accepts that greenhouse gases are warming the planet but contends that responses should be measured by their cost-effectiveness and real-world impact. The book challenges calls for immediate, deep emissions cuts as the primary policy response and urges a broader evaluation of how best to reduce suffering and damage worldwide.

Core argument
Lomborg argues that the most politically and economically viable climate policies are those that deliver the greatest benefits per dollar spent. He questions the efficacy of binding international agreements that aim for steep near-term reductions, saying they would make only a modest difference to global temperatures by the end of the century while imposing high economic costs. Rather than centering policy on rapid mitigation alone, Lomborg recommends prioritizing investments that yield larger, more certain improvements in human welfare.

Evidence and reasoning
The book draws on cost-benefit analysis, economic modeling, and comparisons of alternative public spending options. Lomborg highlights uncertainties in climate sensitivity and the distribution of climate impacts, suggesting that guaranteed improvements in health, infrastructure, and development could outperform marginal temperature reductions in terms of lives saved and suffering averted. He emphasizes that economic growth and technological progress can reduce vulnerability to climate hazards and that targeted adaptation measures can be both pragmatic and effective.

Policy prescriptions
Instead of immediate, aggressive emissions cuts, Lomborg advocates a portfolio approach: increased funding for energy research and development to make low-carbon technologies cheaper, modest carbon pricing to create incentives for innovation, and substantial investment in adaptation measures in vulnerable regions. He also calls for prioritizing development goals such as clean water, disease control, and coastal defenses that can reduce current and future risks. The focus is on scalable, long-term solutions that combine mitigation, adaptation, and human development.

Predicted outcomes
Lomborg contends that this rebalanced strategy would produce greater overall benefits, delivering tangible improvements to health and prosperity while still addressing climate risks over time. He suggests that cheaper, cleaner technologies emerging from intensified R&D would make deep emissions cuts more politically and economically feasible later on. By investing in resilience and innovation now, societies could better protect the poor and respond to the uncertain pace and magnitude of climate change.

Reception and critique
The book sparked intense debate. Supporters praised its emphasis on economics and prioritization, viewing it as a needed corrective to alarm-driven rhetoric. Critics, including many climate scientists and environmentalists, accused Lomborg of underestimating risks, selectively using evidence, and downplaying non-monetary harms such as biodiversity loss and ecosystem tipping points. Questions were raised about his treatment of climate modeling, extreme events, and the ethical implications of delayed mitigation for future generations.

Legacy
"Cool It" amplified discussion about trade-offs, the role of cost-effectiveness in environmental policy, and the balance between mitigation and adaptation. Whether one agrees with Lomborg or not, the book pushed policymakers and the public to think more explicitly about prioritization, the timing of investments, and how to allocate limited resources to reduce suffering and manage long-term risks. Its central provocation, measure climate policy by what it accomplishes, not only by noble intentions, remains a recurring theme in debates over climate strategy.