The Impacts of Global Climate Change


Changes in climate impact the environment, the species that live there, and human health. As temperatures increase, evaporation increases, which increases humidity and rainfall in some places, and drought in others.

Impacts will vary from place to place and affect different populations in different ways. The USEPA has information on the impacts by region, by state, and by sector.


penguinicemelt.jpgThe effects of global climate change include:

  • Greenland and Antarctica ice sheets have decreased
  • glaciers are retreating (melting faster than they reform)
  • ice on rivers and lakes is breaking up earlier
  • plant and animal ranges have shifted
  • trees are flowering sooner
  • sea levels have risen
  • surface temperature has warmed
  • ocean temperatures have warmed
  • increase in frequency of intense rainfall events



flood stage.jpg

What has happened in Illinois?

  • In the past half century, average precipitation has increased by up to 10%
  • The biggest rainfall events have increased by 35% which increases the risk of flooding, which damages infrastructure, private property, and farmland.






Projected change in summer temperatures under different warming scenarios. Summers in Illinois might feel like current summers in Texas or Oklahoma by the end of the century. Source: USGCRP (2009) From USEPA Impacts by Region

What is expected to happen?

  • Winter is expected to be wetter and warmer
  • Spring is expected to be wetter.
  • Summer is expected to be hotter and drier.
  • The lakes will remain ice-free and navigable by cargo ships for more days.
  • Longer growing seasons and increased CO2 will benefit crops, but higher temperatures and drought or flood will hurt crops

What about for Human Health

  • Hot weather increases ground level ozone, causing health problems for humans.
  • Heat stroke and dehydration are increased with higher air temperatures.
  • Climate change has allowed disease carrying ticks and mosquitoes to expand their range, putting more people at risk.
  • Algal blooms are expected to increase in the Great Lakes, affecting water quality and fisheries.
  • Stormwater runoff is expected to increase, also affecting water quality and fisheries.
  • Warmer temperatures cause declines in livestock productivity.

Everyone is susceptible to adverse health conditions, but who is most vulnerable?

  • Older people are less able to regulate body temperature.
  • Children are at greater risk of respiratory problems due to poor air quality.
  • People with pre-existing health conditions such as obesity, asthma, heart disease, diabetes
  • People with underlying mental health conditions may suffer increased stress.
  • People with reduced access to healthcare, water supplies, and transportation
  • People with lower incomes who may not be able to afford increases in energy costs or to rebuild after catastrophe
  • People who work outside


For more information, see the USEPA Climate Change Impacts for the Midwest

and Climate Change Impacts on Human Health


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