Global Warming and Geo-engineering

When we talk about Global Warming we take a look on the Climate models. Those models assume different possible scenarios to predict future global warming, however it is difficult to estimate how much the greenhouse gas emissions will grow.

According to IPCC, the Earth will warm between two and sig degrees by 2100, depending on how fast carbon dioxide emissions grow (http://earthobservatory.nasa.gov/Features/GlobalWarming/images/ipcc_scenarios.png). Whereas the models that assume scenarios where people will burn more and more fossil fuel have the highest temperature rise; other scenarios assume a greenhouse gas emissions will grow slowly, giving lower temperature predictions.

Last IPCC report says Human activity has been the main cause of the observed warming since the mid-20^th century. Moreover, this influence has been detected in warming of the atmosphere and the ocean, in changes in the global water cycle, in reductions in snow and ice, in global mean sea level rise, and in changes in some climate extremes.

Some scientists have been looking for solutions in order to modify Earth’s environment for controlling global warming and that is what we know as Geo-engineering. The Geo-engineering proposals include different ways to reduce temperature and CO2, cloud-whitening or ocean fertilization, for instance.

We need to assess the risks geo-engineering can cause to the Earth and its inhabitants since we don’t know for sure how the system will react to the proposed changes. The Ocean fertilisation could sink CO2 in the ocean floor, yet the CO2 biological and physical pump between the ocean and the atmosphere is very complex system (http://www.whoi.edu/cms/images/biological-pump_104615.png) and we don’t know how this system will change; so more research need to be done for understanding the implications of Ocean fertilization.

Would not be better to make more effort on reducing our CO2 emissions, rather than preventing the warming with geo-engineering? I definitely think so, we can try to fix the problems that we already have before we cause more troubles. 

Useful links: 
BBC News - Geo-engineering
http://news.bbc.co.uk/2/hi/technology/8338853.stm
http://www.bbc.co.uk/news/science-environment-19371833
IPCC - http://www.ipcc.ch/news_and_events/docs/ar5/ar5_wg1_headlines.pdf
NASA Earth observatory - Global warming http://earthobservatory.nasa.gov/Features/GlobalWarming/page5.php
WHOI - Ocean fertilisation http://www.whoi.edu/ocb-fert/page.do?pid=38315

Week 4 reflections on Climate Change course, University of Exeter.