In Cool It, Lomborg argues his view that many negative impacts of climate change are overstated, and mitigation approaches are expensive and have poor return on investment; he instead proposes alternative solutions.

In Cool It, Lomborg argues his view that many of the elaborate and expensive actions being considered to stop global warming will cost hundreds of billions of dollars without the same return on investment, often are based on emotional rather than strictly scientific assumptions, and may have very little impact on the world's temperature for centuries.

He attempts to dispel what he views as climate change "myths", arguing that it is too soon to say if Greenland's ice is melting, and that the impacts of sea level rise, extreme weather, droughts and floods are overhyped.

IPCC lead author Brian O'Neill[5] wrote a mixed review of Cool It, concluding:[6] [...] Bjorn Lomborg is like the Oliver Stone of climate change.

Although Friel engages in some bothersome overkill, overall his analysis is compelling.A feature-length documentary film adaptation of Cool It was released in 2010, which features Lomborg.