Chaos

There are so many other effects of climate change, not just warming by a few degrees. Not only would ecosystems worldwide be destroyed and sea levels rise, but entire climate systems would be disrupted, ruining our way of life as crops fail and resources become scarce, political divides would arise and deepen. The world as we know it would disappear.

For example, one potential outcome for Britain and the rest of western Europe is a mini ice age: as the melt water from the arctic flows south it could dilute the gulf stream and north atlantic drift which keeps that part of the world warm resulting in a temperature drop of 10-15 degrees C or more. The results of which would be catastrophic.

There are many theories like this, some of which are purely speculative, but many of the actions we need to take to reduce potential climate change and its effects would benefit the world even if the worst-case scenarios didn't occur and so should be taken anyway. Things like developing carbon capture & storage, reducing the use of fossil fuels, and bolstering infrastructure in general.

Here are some links that you may find interesting:

A world map with projections of the consequences of a worldwide average rise of 4 degrees C (7 degrees F) - http://webarchive.nationalarchives.gov.uk/20100623194820/http://www.actoncopenhagen.decc.gov.uk/content/en/embeds/flash/4-degrees-large-map-final

A world map with projections of how sea level rise would affect the world -
http://flood.firetree.net/

This is a site showing changes in average temperature and precipitation in the US and across the world:
http://www.climatewizard.org/

I'm doing what I can to stop climate change, but I can't do it alone. If we pull together, we can make a difference and make the world a better place for future generations.