New geological data indicate that marine life is somewhat resilient to warming in the tropics. Chris Fokkema, Earth scientist at Utrecht University, discovered that tropical algae were largely unaffected by a number of periods of global warming of up to 1.5 degrees Celsius in the distant past. These unicellular organisms form the basis of food webs and are generally very sensitive to rising temperatures. Previous studies of periods of even greater warming showed a dramatic decline in these organisms. "Somewhere beyond those 1.5 degrees, a tipping point occurs."