Markey asked:

"Can you talk a little bit about how you view the development of technologies today, and what you believe is possible technologically if we get the policies right in terms of solving this problem."

After commenting on a number of technologies, Holdren said:

"We need to develop and deploy approaches to nuclear energy that can minimize the liabilities that have inhibited expansion of that carbon-free energy source up until now. We need to see if we can make fusion work. This is a quest in which I've been engaged since 1965. Again I started it at MIT my work in that domain. At that time people thought fusion was 15 years away. Now people think it's 40 or 50 years away. We need to shrink that time scale again by increasing the investment for making that domain."