Climate Change

Topics include: myths and facts of climate change; basic atmospheric science and climate modeling; the nature of scientific knowledge; relationships between scientific knowledge and social and cultural values; contributions that the social sciences and humanities can make to public debates on climate change.

Global Dimming: Should we care?


What is Global Dimming?

A widespread decrease in surface solar radiation caused by particulates in the earth’s atmosphere.  Over the last 50 years, scientist have noticed a trend of solar irradation across the globe.  The more particulates in the atmosphere, the higher the degree of dimming occurring because of thicker cloud formations.


What are the causes of Global Dimming?

  • Gas Absorption
    • Nitrogen Dioxide (NO2)
    • Methane (CH4)
    • Carbon Dioxide (CO2)
  • Water Vapor
  • Air pollution

Revelations:

Currently the globe is experiencing a decrease in solar radiation by 2.7% per decade.  However the most affected areas of radical dimming occur in industrialized areas of the world.

Mainly China is currently experiencing the heaviest amount of solar irradiation at about 10% per decade.  The Former USSR region currently experiences 3% to 5% solar irradiation per decade.

globalDimmingModel

How does Global Dimming relate to Global Climate Change?

Global dimming contributes to less solar radiation and results in bouncing back the sun’s rays and reduce the global temperature.  However, greenhouse gases that we exceedingly emit into the atmosphere continue to grow and still make it possible for the temperature to rise.  In areas where dimming is significant (i.e. China), it may seem that the earth is cool, but once particulates are removed from the atmosphere, the temperature will rise, dramatically.

An example of such an event occurring, we can look at the continent at Europe.  The countries in that continent have undergone various reform to regulate green house gas emissions.  When the particulates reduced from various sources of fossil fuel burning (shut down of factories, hybrid cars), the temperature rose.  In the summer of 2003, France recorded the highest recorded temperatures which led to nearly 15,000 deaths related to heat stroke.

Aside from that, continual pollutants into the atmosphere can only generate negative outcomes:

  • More emissions cause respiratory problems for the rest of the population.
  • Global Dimming cause severe weather pattern changes which result in extreme droughts in various areas.
  • Solar irradiation can reduce the production of agricultural crops.

Global Dimming serves as a reminder that we must deal with green house gases and not only reduce our current emissions.