References

1.Voice of America. (2019, Dec. 3). UN Report: Last 10 Years Likely the Hottest Decade on Record | Learning English. Retrieved from: https://learningenglish.voanews.com/a/un-report-latest-10-years-likely-the-hottest-decade-on-record/5191180.html

2.NASA. (2017, January 19). Climate Change: How do we know? (Ed. Newsela Staff). Retrieved from http://climate.nasa.gov/evidence/

3.NASA. (2017, January 19). A Blanket Around the Earth. (Ed. Newsela staff). Retrieved from http://climate.nasa.gov/causes/