• Earth is Warmer. Has the Atmosphere Warmed too? Research teams differ on trend of atmospheric warming
  
  
• The Nations's Plan for Research in Climate Change

  • Editor's comment on the Climate Change Science Plan

  
  
• CLIMATE BRIEFS:

  • Satellites Observe Longer Melt Season in the Arctic
  • Large Cities boost rainfall downwind: Focus on Houston
  • Tropical Sea Water Saltier, Polar Water now Fresher
  • Northern Forests Remove Half the Missing CO₂
  • Oceans May Soak up Future Warmth

  
  
• New Climate Products:

  • US Drought Monitor
  • Review of Climate in Year 2003
  • Forecast for Spring 2004
    
    
• Climate and Collapse of Societies

    A dilemma has bedeviled Earth science for the last 25 years. You might think that the atmosphere must be warming if the surface of the Earth (where people read thermometers) is warming, but you might well be wrong. The “ocean of air” should warm as fast as the surface does, since that is a consequence of the “greenhouse effect”, which explains why carbon dioxide(CO₂) may be raising global temperatures. Since CO₂ absorbs outgoing thermal radiation from the Earth's surface, and re-radiates it back to Earth, you might expect the gas (and the surrounding air) to warm up in step with the surface. Nearly all climate “models” predict this behavior. But Planet Earth does not behave this way! Data from weather balloons and satellites suggest that the lower atmosphere either has not warmed at all, or has warmed much less than the Earth’s surface over the last quarter century of truly global measurements.

    This is perplexing enough to Earth scientists, but there’s more . . . . We can use either weather balloons or satellites to measure the temperature of the lower atmosphere. The technology of weather balloons is simple and the data exist for about 70 years. Bur since balloons are launched only from land areas (30% of the Earth), their data cannot give a global picture. Weather satellites do observe the temperature of the whole globe, but have done so only since 1978. Data from both sources are seriously flawed for detecting long-term climate changes. Which source should you trust?

    Also, the two main research teams that specialize in measuring the temperature of the atmosphere with satellite data do not agree on the rate that the atmosphere is warming, or even (until recently) if it is warming at all. In the past year, their differences have narrowed. Reasons for arriving at different temperature trends are becoming clear, but much remains uncertain on the whole question.

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