Biodiversity is inextricably linked to climate, but these interactions are not straightforward. This policy brief examines the interface from both sides. The authors firstly explore the impacts of global warming on biodiversity, from increasing the rate of extinctions to more subtle changes in reproductive cycles and growing seasons. 

Turning the tables, they then look at how biodiversity affects climate change. For example, when forests are felled, both local weather and global climate are affected as the removal of trees causes shifts in moisture and temperature, and stored carbon is released to the atmosphere. Similarly, changes in oceanic algal populations can, through a series of natural processes, actually lower air and water temperatures.

With biodiversity and climate change so closely linked, the authors explain why a strong, integrated response is needed, although there are numerous hurdles at the international level. National programmes with a two-pronged approach possibly hold more promise, but even here, governments will need to restructure the way they handle environmental issues before real progress can be made.

The Earth’s climate has gone through many periods of significant change throughout its history. Whether they featured warming or cooling, these shifts have inevitably had important ecological impacts: the fossil record shows that episodes of major climate change have coincided with a number of mass extinctions of species over the past 500 million years.

The current episode of global warming, however, is different from the rest, as it is fuelled mostly by human activities – specifically the emission of greenhouse gases, chiefly from burning fossil fuels. Other human activities that contribute to climate change include agriculture and changes in land use that lead to the release of methane, carbon dioxide, nitrous oxide, and some industrially produced gases.

Increased emissions of all these gases are leading to build-up of greenhouse gases in the atmosphere. Carbon dioxide is accumulating faster than at any time over the past 20,000 years. And in the immediate future, rates of increase in global temperatures are expected to be the greatest for the last 10,000 years