The history of climates is understood because of evidence left in tree rings, layers of ice in glaciers, ocean sediments, coral reefs, and layers of sedimentary rocks. For instance, air bubbles trapped in the glacial air can provide the history of greenhouse gases for back more than 800,000 years. Thus, chemical composition of the ice offers clues to the average global temperature and construction of paleoclimates. These records coupled with climate models suggest warmer past ice ages even warmer than today. However, these records also recommend that the current climate is warming very fast than past warming events. In the past million years, the Earth’s temperature increased only 4–7 °C for every 5000 years. However, in the past century, the temperature had raised 0.7 °C which is about ten times higher than the rate of ice age (Riebeek 2010).
- Black, R. (2013). A brief history of climate change [online]. BBC. Available: http://www.bbc.com/news/science-environment-15874560 [Accessed 27 Apr 2018].
- Burgess, R., Deschenes, O., Donaldson, D., & Greenstone, M. (2017). Weather, climate change and death in India. Working paper LSE.Google Scholar
- Edenhofer, O., Pichs-Madruga, R., Sokona, Y., Farahani, E., Kadner, S., Seyboth, K., Adler, A., Baum, I., Brunner, S., & Eickemeier, P. (2014). IPCC, 2014: Summary for policymakers. Climate change.Google Scholar
- FAO. (2015). In A. Elbehri (Ed.), Climate change and food systems: Global assessments and implications for food security and trade. Rome: Food Agriculture Organization of the United Nations (FAO).Google Scholar
- IPCC. (2005). IPCC special report on Carbon dioxide capture and storage prepared by working group III of the IPCC. metz, 80., O R Davidson, H. C. de Coninck, M. Loos, and L. A. Meyer. Cambridge: Cambridge University Press.Google Scholar
- IPCC. (2007). IPCC fourth assessment report: Climate change 2007 [Online]. Available: https://www.ipcc.ch/publications_and_data/ar4/wg1/en/faq-1-3.html [Accessed 16 Apr 2018].
- Molina, R. (2014). El Niño: Is 2014 the new 1997? [Online]. Available: https://science.nasa.gov/science-news/science-at-nasa/2014/19may_elnino [Accessed 27 May 2018].
- NASA. (2018). Climate change: How do we know? [Online]. Available: https://climate.nasa.gov/evidence/ [Accessed 18 Apr 2018].
- NOAA. (2018). NOAA’s Annual Greenhouse Gas Index .[Online]. Available: https://www.esrl.noaa.gov/gmd/aggi/. [Accessed 27 May 2018].
- Riebeek, H. (2010). Global warming: Feature articles .[Online]. Available: https://earthobservatory.nasa.gov/Features/GlobalWarming/page2.php [Accessed 17 Apr 2018].
- Uprety, D. C., & Reddy, V. R. (2016). Crop responses to global warming (pp. 1–125). Dordrecht: Springer Science.Google Scholar