What do we know and what don’t we know about climate change and biodiversity?

I will highlight key perils posed by climate change to Earth’s biodiversity while also emphasizing areas where our knowledge is alarmingly tenuous. As global temperatures continue to rise in the coming decades, many cool-adapted, high-elevation specialists in tropical forests could be among the most imperilled species on earth. However, many other possible changes are poorly understood.

Projections of future climates vary greatly, particularly at local and regional scales. Our capacity to predict future rainfall is especially poor—a crucial weakness because rainfall greatly influences the vulnerability of tropical forests to destructive fires. In addition, a heated debate is raging between those who believe undisturbed tropical forests are functioning as a net carbon sink, because forest productivity is increasing in response to rising CO₂ levels; versus those who assert that forests are becoming carbon sources because higher temperatures are increasing plant respiration rates and thereby slowing plant growth. This debate has profound implications for future climates and for understanding the global carbon cycle. In short, there is a great deal about future climate change that we do not yet know. 

About the speaker

William Laurance is a Distinguished Research Professor and Australian Laureate at James Cook University in Cairns, Australia. An environmental scientist whose work spans the tropical world, he has written eight books and over 600 scientific and popular articles. He is a fellow of the Australian Academy of Science and the American Association for the Advancement of Sciences, and former President of the Association for Tropical Biology and Conservation. He has received many professional honors, including the Heineken Environment Prize, BBVA Frontiers in Ecology and Conservation Biology Award, the Society for Conservation Biology’s Distinguished Service Award, and the Zoological Society of London’s Outstanding Conservation Achievement Prize. He is director of the Centre for Tropical Environmental and Sustainability Science at James Cook University, and founded and directs ALERT—the Alliance of Leading Environmental Researchers & Thinkers—a science-advocacy group that reaches over 1 million readers weekly. He is a four-time winner of Australia’s Best Science Writing Award.