In a sign of the changing times, a Greenpeace activist invited to address the 1996 Australian Coal Conference warned delegates their companies would be "dinosaurs" if they stay with coal alone -- or they could diversify into renewables like mammals adapting to changing times. Keith Tarlo of Greenpeace told the conference, held in Gold Coast, Australia in May, that energy technologies such as wind and solar and efficiency would help fulfil the world's energy needs while reducing global warming from CO2 emissions. He said significant reductions in net greenhouse emissions were technically and economically possible over the next 50 to 100 years. Otherwise, a worst-case scenario would be the world's surface temperature increasing by 4.5 degrees Celsius by 2100. Tarlo asked the delegates whether their companies wanted to be in the coal business or the energy business. "I want to ask you whether the company you work for will be a dinosaur company staying with coal, the old unsustainable technologies and fuels," he said. "Or will your company be a mammal adapting to changing times, diversifying into solar energy, becoming a total energy company in advance of the capital markets and financial markets doing it for you."