How can I become an environmental scientist when I get older?

Dan answers: Environmental science involves bringing together information from a wide variety of fields, particularly chemistry, physics, and biology. And as with all science, a solid background in mathematics is essential -- so don't be scared off by algebra and calculus. (Don't tell anyone, but math is actually fun!). Most of all, never give up on the idea that we can figure out better ways to protect the environment.

Do you have figures for 1997 U.S. CO2 emissions?

Will American families' energy costs really rise $70 per year to comply with the Kyoto Protocol?

Dan answers: We (my colleagues here at NRDC, as well as environmentalists and others who study global climate change) think that saving the planet is cheap at twice the price -- but that it will probably cost half as much or less. That figure is from a Clinton Administration analysis. The analysis doesn't take into account the fact that a number of energy efficiency and clean energy technologies currently exist but are not being used, therefore it doesn't consider the economic benefits to consumers of putting these technologies into play. And, of course, the analysis doesn't acknowledge the environmental and economic benefits of reducing pollution and curbing global warming.

Why can't developing countries cut their emissions, especially with the help of the U.S. and other countries?

Dan answers: There are many opportunities to improve technology to limit emissions from developing countries. But because countries like China and India are industrializing rapidly, it is likely that their total pollution output will continue to increase for some time. Developing countries are already taking many steps to promote sustainable development -- such as reducing fossil fuel subsidies and promoting renewable energy sources -- but countries like India and China are reluctant to make new international commitments when the United States and other industrialized countries have failed to live up to the promises that they made at the 1992 Earth Summit in Rio.

What happens with issues not resolved at the Kyoto conference?

Dan answers: The negotiations will continue at future conferences, with NRDC and other environmentalists following the issues carefully. One of the main unresolved issues is that of the role of developing countries, which will be revisited at the next conference, scheduled for November in Buenos Aires. Opponents of action on global warming will attempt to use this issue to block U.S. ratification and implementation of the agreement. The hypocrisy of the oil industry in this regard is stunning. After campaigning for a year on the need for developing country participation (all the while telling developing countries to resist commitments), the oil industry is now calling for President Clinton to submit the treaty to the Senate immediately -- so that it will be voted down before serious negotiations with developing countries have begun. Congress will need to hear an outpouring of public support for the Kyoto accord in order to counteract the industry opposition.

I teach chemistry and would like to know about PFCs and SF6: what are they and what are the major sources of these two gases in the atmosphere?

Dan answers: PFCs are perfluorocarbons, particularly carbon tetrafluoride (CF4) and carbon hexafluoride (C2F6). These compounds are produced as a byproduct in aluminum smelting and are also used in some cases as a substitute for chlorofluorocarbons, which were phased out because of their impact on the ozone layer.

Gram for gram, sulfur hexafluride (SF6) is the most potent greenhouse gas ever evaluated. It is used primarily as an insulator in electrical transmission and distribution systems. I'm happy to say that the emission reduction requirements agreed to in the Kyoto Protocol cover these powerful greenhouse gases.