<Your Name>
<Address here>
<Your contact information>
<Date>
<Name>
<Send to Address>
Dear Honorable Senator < Name>,
I am writing you to express my concern with climate change and the effect it has on animal species. As you are probably aware, scientists have determined that current climate change trends are caused in part by anthropogenic greenhouse gases, which are trapping heat in Earth’s atmosphere and warming the climate at an unprecedented rate over the past 200 years¹.  The focus of this warming trend is often on the physical changes happening, and expected to happen, to the environment, including melting sea ice, more severe weather patterns, rising sea levels and regional warming. Studies on the effects of these changes on animal species have been documented around the planet, but have not received adequate attention. The changes in the environment are happening at a rate that is affecting the phenology, distribution, success, and population size of animal species across the taxonomic and geographical spectrum². Scientists predict a high extinction rate if climate change continues at its current rate, and a change in the biodiversity and balance between species that has been formed through adaptive measures over the years³.  
I write now to ask that you support legislation to reduce the greenhouse gas emissions that are causing climate change. The U.S. House of Representatives has passed a bill that would require the United States to reduce its emissions of greenhouse gases 17 percent by 2020 compared to 2005 levels. The Senate has not passed a similar measure but there are three bills in the senate S. 1151, H.R 759, and H.R 2828, which would cap emissions of the six greenhouse gas emissions as specified by the U.N convention. Energy initiatives also have to be a priority. Climate change needs to be a priority at the state and federal level in order to reduce our emissions before the effects of climate change have widespread, irreversible consequences on the physical and biological systems of the planet. I ask you to support legislation through the senate and to be an active member in creating legislation to reduce our emissions and become a leader in climate change action. I also ask you to take this message to the congress and push for the United States cooperation in international treaties to create emission standards and to push for incentives and taxes that will help reduce emissions in the business and residential sector.
Consider the future of biodiversity, of the planet, and of humans, and take a stance on climate change before it is too late. I look forward to your response.
Sincerely, 
 <Your Name>

¹U.S. Environmental Protection Agency, 2010. Basic Information: Climate Change. Retrieved on March 30, 2010 from http://www.epa.gov/climatechange/basicinfo.html. 
²Intergovermental Panel on Climate Change, 2002. Climate change and Biodiversity: IPCC technical paper V. Retrieved on March 22, 2010 from http://www.ipcc.ch/pdf/technical-papers/climate-changes-biodiversity-en.pdf 
³Intergovernmental Panel on Climate Change (IPCC), 2007. Synthesis of observed impacts. Climate change 2007: Working group ll: Impacts, Adaptation, and Vulnerability. Retrieved on 11 March 2010 from
http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch19.html 
▫Reuters, 2010. Obama to push Climate change in white house meeting. Retrieved on March 30, 2010 from climate legislation for action letter.htm.