Showing papers on "Global warming published in 1982"

The rise of global mean sea level as an indication of climate change.

Abstract: Rising mean sea level, it is proposed, is a significant indicator of global climate change. The principal factors that can have contributed to the observed increases of global mean sea level in recent decades are thermal expansion of the oceans and the discharge of polar ice sheets. Calculations indicate that thermal expansion cannot be the sole factor responsible for the observed rise in sea level over the last 40 years; significant discharges of polar ice must also be occurring. Global warming, due in some degree presumably to increasing atmospheric carbon dioxide, has been opposed by the extraction of heat necessary to melt the discharged ice. During the past 40 years more than 50,000 cubic kilometers of ice has been discharged and has melted, reducing the surface warming that might otherwise have occurred by as much as a factor of 2. The transfer of mass from the polar regions to a thin spherical shell covering all the oceans should have increased the earth9s moment of inertia and correspondingly reduced the speed of rotation by about 1.5 parts in 108. This accounts for about three quarters of the observed fractional reduction in the earth9s angular velocity since 1940. Monitoring of global mean sea level, ocean surface temperatures, and the earth9s speed of rotation should be complemented by monitoring of the polar ice sheets, as is now possible by satellite altimetry. All parts of the puzzle need to be examined in order that a consistent picture emerge.

Towards regional scenarios for a CO2-warmed Earth

Abstract: Measured and projected increases in carbon dioxide content of the atmosphere point towards a significant global warming. The regional effects of such a warming will be of primary importance in determining the social and economic consequences. Four methods of arriving at tentative regional scenarios are discussed and illustrated by application to Australia and New Zealand. Methods used include numerical modelling, extreme warm and cold year ensembles, dynamical/empirical reasoning and palaeoclimatic reconstructions from the Hypsithermal. A surprising degree of consistency is revealed between the various approaches to a scenario for a CO2-warmed Earth and the climatic conditions which prevailed during the Hypsithermal. The best overall analogy to a CO2-warmed Earth seems to be this epoch, especially as recent evidence suggests it to be one of higher CO2 concentrations. High priority should be given to further investigations using numerical models which include an interactive dynamic ocean and hydrologic cycle including variable cloudiness, as well as more detailed reconstruction of climatic conditions during the Hypsithermal in areas sensitive to any circulation changes.

The greenhouse effect.

Abstract: The climate change induced by man-made releases of carbon dioxide and other trace gases is discussed The level of carbon dioxide in the atmosphere has increased from an estimated 293 ppm in 1880 to 335 ppm in 1980, due mainly to the increased use of fossil fuels That level is expected to double in the next century Several carbon dioxide models are discussed, along with trends of global temperatures The effects of the global warming are also discussed along with future research needs (JMT)