During his confirmation hearing, Holdren told the senators that he will have four Senate-confirmed associate directors for science, technology, environment, and international affairs. He said he plans to revive the National Science and Technology Council to ensure better coordination and communication among federal science agencies.

When pressed about the Administration's approach to the regulation of carbon dioxide emissions, Holdren cited the president's position of aiming to reduce them "by something like 80 percent in 2050." That reduction would provide a "reasonable chance of confining the global average surface temperature increase to about 2 degrees Celsius." He said it would be "a great challenge to get there," adding that it would offer tremendous opportunities in innovation and subsequent job creation to maintain and improve the U.S. competitive position. Holdren was optimistic that China and India would engage in the process since climate change is hurting their nations. He predicted that there will be much discussion about emission control approaches and provisions, and told the senators, "it's going to be a long slog. I don't want to kid anybody. This is going to be tough. . . . "

Holdren said, "The cost and complexity of cutting-edge accelerators, telescopes, and certain experimental energy technologies, such as the ITER fusion experiment, are good reason in themselves for sharing the costs and risks internationally." "I have been involved in international cooperation on fusion and other energy technologies since 1971 and I will be most eager to put the insights derived from that experience to good use at OSTP, " he said.