As the United Nations Climate Change Conference continues in Copenhagen, atmospheric scientist Katharine Hayhoe, MS, offers her take on what needs to happen.

“It is encouraging to see global leaders discussing the ways climate change may affect us and how we can contribute toward a solution,” says the research associate professor at Texas Tech University’s Department of Geosciences and coauthor of A Climate for Change: Global Warming Facts for Faith-Based Decisions.

Interestingly, her 224-page book examines Christian views on climate change. In an effort to dispel many of the myths and misconceptions that cloud Americans’ views, Hayhoe and coauthor Andrew Farley (a pastor) address why Christians should care about global warming and why temperature increases are more than “just a cycle.”

To avoid climate change’s most severe effects, we must globally stabilize the concentration of heat-trapping gases in the atmosphere at no more than 450 parts per million (ppm) by 2050, Hayhoe says. This limit is designed to avoid a global average temperature increase exceeding 3.5°F—a benchmark she and other scientists believe could wreak increasing environmental havoc. (Others are pushing for a 350-ppm limit.)

“If we wait until 2020 to start emission reductions, we’ll have to cut twice as fast than if we start in 2010 to meet the same target,” says Hayhoe, who contributed to the Nobel Prize-winning United Nations Intergovernmental Panel on Climate Change in 2007.