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What respiratory problems may occur...
Explain the 30-year levelling...
What's next with the global warming treaty...
What's in store for Florida...
What on earth are bunker fuels...
How is CO2 measured, reduced...
What respiratory problems may occur from increasing carbon dioxide levels?
Dan answers: Carbon dioxide does not directly cause respiratory problems at the levels expected to occur in the atmosphere. Global warming, however, can enhance smog formation, which would cause respiratory problems. Also, the same sources that release global warming pollution -- most importantly automobiles and power plants -- also release large quantities of nitrogen oxide and sulfur oxide emissions which cause smog and respiratory problems.
Did the global temperature increase level off from 1940 to 1970 because of particulates? If so, why has the increase now continued?
Dan answers: Observed changes in global temperature over the last century result from a combination of many factors, including greenhouse gases, particulate matter, small changes in the output of the sun, and natural variability. Increases in carbon dioxide and other greenhouse gases is the only credible explanation for the overall warming trend seen in the record. The explanation of some of the details of the records -- such as the relatively level temperatures from 1940 to 1970 -- are more difficult to pin down because natural variability plays a larger role when one looks at shorter periods of time. Increases in particulate matter -- derived sulfur dioxide emitted when coal and oil is burned, which has a cooling effect -- appears to be the best explanation for the relatively flat temperatures from 1940 to 1970. This effect has not stopped, but pollution controls have brought about a leveling off in sulfur dioxide emissions, while carbon dioxide and other greenhouse gas pollution continues to accumulate in the atmosphere. As a result, the cooling effect of particulate matter is expected to be increasingly overwhelmed by the warming effect of greenhouse gases.
What's next with the global warming treaty? When will it take effect?
Dan answers: The treaty -- known as the Kyoto Protocol -- becomes effective once countries representing 55% of industrialized country emissions have ratified it, and then in each additional country as that country ratifies it. President Clinton has said that he won't even send the treaty to the Senate for consideration until after "meaningful participation" by developing countries is secured and additional details are worked out at the next major meeting, scheduled for Buenos Aires, Argentina in November. (See NRDC's analysis of the treaty.)
In the meantime, environmentalists have our work cut out for us building support for the treaty. Industry lobbyists will be working overtime to keep it from being ratified, and a number of Senators have already expressed their opposition to it. We will also continue to promote the development of technologies and mechanisms for meeting the goals of the treaty -- for example, new building standards that would trim U.S. greenhouse gas emissions by 5%.
What will be the impacts of global warming on South Florida?
Dan answers: Within the next one-to-two decades, the environment of South Florida could be significantly affected by global warming as higher water temperatures and rising sea levels add significantly to the stress on fragile ecosystems such as the Everglades and coral reefs. Within 50 years, significant areas of South Florida could be submerged. Within 100 years, if nothing is done, the Keys and most of the Everglades would be submerged. See Figure 16 on the Vulnerabilities and Potential Consequences page of the White House Climate Change site for a map illustrating areas of South Florida subject to inundation after a 1-meter rise in sea level.
Okay, you asked for it: what are "bunker fuels"?
Dan answers: I guess we did. Actually, I'm impressed that you've been reading our dispatches closely enough to notice. "Bunker fuels" refer to fuels used in international transportation, such as aircraft flying from Washington to Osaka or ships travelling in international waters. These fuels are currently not accounted for in national inventories of greenhouse gas emissions, implying that no one is taking responsibility for controlling the associated global warming pollution. This is a significant loophole that has not yet [as of 12/8/97] been closed off in the Kyoto talks.
How are CO2 emissions measured and what were U.S. levels in 1990? How can emissions be cut to below those levels?
Dan answers: CO2 emissions are calculated from energy consumption statistics. U.S. emissions were about 4.9 billion tonnes in 1990, and current emissions are about 10% higher. By 2010, emissions could be 30% above 1990 levels if there are no changes in policy and if government forecasts are correct. Emissions could be reduced to 1990 levels, and indeed, below, by a combination of efficiency measures in homes, offices, and factories, and by making automobiles that are much more fuel-efficient. Pollution from power plants can also be cut substantially by switching from coal to natural gas and renwable energy sources.
Published by the Natural Resources Defense Council -- contact us at nrdcinfo@nrdc.org