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TECHNICAL BRIEFING FOB INTERGOVERNMENTAL NEGOTIATING COMMITTEE MEETINGS UNITED NATIONS.
NEW YORK. MAY 7 1992
MEMORANDUM: CAN WE AVOID ECOSYSTEM DAMAGE FROM CLIMATE CHANGE?
TO: INC NEGOTIATORS
FROM: Dr. Thomas J. Goreau, President, GCRA
1. IPCC projections for future climate change are based on assumed sensitivities of temperature and sea level to carbon dioxide increase that are 1O times less, and 1250 times less respectively, than have actually taken place in the past. The last time global temperatures were 1-2 degrees C above today’s values, sea level was 5-8 meters higher, compared to the 0.1 to 0.3 meters projected by IPCC. These observed changes imply that current projections may seriously underestimate potential long-term rises in sea level and temperature.
2. Coral reefs around the world are bleaching from heat shock stress and corals are increasingly dying as episodes increase in frequency and intensity. Bleaching took place after “hot spots”, regions of ocean temperature 1 degree C above normal, hit reef areas during the hottest months. Mass bleaching was unknown before the 1980s. Reefs which have escaped hot spots by luck are certain to be damaged if they continue. Major components of tropical marine biodiversity, fisheries, tourism, and shore protection are at serious risk from global warming.
3. Halting global warming requires stabilization of C02 concentrations in the atmosphere, not just stabilizing emissions. This requires both reduced supply of C02 to the atmosphere from fossil fuels and increased removal of C02 by protecting remaining forests and reforesting currently degraded areas. Simultaneous supply and demand-side measures are needed. Rapid global increase in biomass is essential because this is the only practical measure which can significantly reduce C02 concentrations within decades. Even drastic emissions reductions require over a century to have major impacts on C02 levels. Reforestation and increased energy efficiency together can affordably stabilize C02, providing an interim measure until non C02-producing energy sources replace fossil fuels.
4. Forest protection is not a sectoral issue. Boreal forests are the most efficient carbon sinks because they hold on to carbon for the longest in wood and soil. Tropical forests are inefficient, they hold on to carbon for a short time before returning it to the atmosphere. However, increased tropical forest cover is also critical because it is the most important ecosystem for reducing the atmospheric lifetime of C02 and the total heat each additional molecule adds to the atmosphere. Global warming will make all forests less efficient carbon sinks. Oceans are an extremely inefficient sink, unless they are dangerously polluted.
5. The Convention at present Is Inadequate to protect coral reefs from climate change. It requires stronger commitments to reduce atmospheric greenhouse gas concentrations. Global, long-term, wholistic thinking Is needed on all sides now before it is too late to save and restore reefs and forests.