This Week in EPA Science

By Kacey FitzpatrickResearch Recap graphic identifier

Fall foliage is at its peak in Washington DC—everywhere you look the leaves are changing from green to vibrant shades of red, yellow, gold, and orange. Why do the leaves change color? Well, it all starts with science! Check out this lesson from the USDA Forest Service.

Chlorophyll, one of the necessary ingredients for photosynthesis, is what makes leaves green. As the summer turns into fall, the days get shorter and there is less and less sunlight. This signals the trees that winter is coming and they will prepare to use their stored fuel instead of making it. Then there is no need for chlorophyll and the green colors fade away to the yellows, and oranges that were there all along! And all those red leaves? That is the result of warm, sunny days and cool, autumn nights.  Leaves keep producing sugars but the tree doesn’t take as much, leaving nutrients trapped in the leaves and brilliant shades of red for us to look at!

Want more science? Here is some EPA research we are highlighting this week.

  • National Chemistry Week!
    It’s National Chemistry Week—a community based program to educate the public about the importance of chemistry to our quality of life. EPA’s safer chemicals research leads the development of innovative science to support safer, more sustainable use of chemicals.

    Read more about it at EPA’s Safer Chemicals Research page.

  • A Sustainable Future for All
    EPA along with the European Union delegation to the U.S., the World Resources Institute, and the European Environment Agency organized the EU Rendez-Vous on environment sustainability. The Rendez-Vous featured senior European and U.S. leaders discussing the efforts to measure and assess progress towards a sustainable and efficient economy.

    Check out the video summary of the event.

Photo of the Week

Several people on horseback travel down a winding path









In September 2015, EPA researchers covered 20 miles of rugged terrain on horseback and on foot to retrieve government equipment from the face of Collier Glacier in the Three Sisters Wilderness area of the Deschutes National Forest, Oregon.


If you have any comments or questions about what I share or about the week’s events, please submit them below in the comments section!

About the Author: Kacey Fitzpatrick is a student contractor and writer working with the science communication team in EPA’s Office of Research and Development.

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