LOL! The esteemed Dr. Happer was trying to do just that to the Senate! His point was that we have had many extreme climate changes on the Earth over millions of years; some more extreme than others. His point was that there were times, which were amenable to life, which had higher CO2 counts than we have now, so obviously, life, and the Earth survived them. He also made the point that warmer temperatures are not necessarily a BAD thing, because it makes for better growing conditions to help sustain human life on the planet.
THAT was the key phrase. Most extinctions happen when climate changes rapidly -- and that's the danger being anticipated now. Ecosystems can adapt when climate changes over millenia -- but not decades.
warmer temperatures are not necessarily a BAD thing,
Sure, human civilization might be able to adapt to 2-3 C of warming -- if it happened over 300-400 years. Over 100 years; Melting Andean Glaciers Could Leave 30 Million High and Dry
"With water supplies, agriculture, and power generation at risk, the World Bank and the funding agency Global Environment Facility are working together to develop adaptation strategies for local communities."
I recommend reading the full article; quite sobering. And this represents only a regional sampling. China is already quietly freaking out about the loss of water supply from Tibetan glaciers.