Recent [[model (abstract)|model]]s forecast that even in the unlikely event of greenhouse gases stabilizing at present levels, the earth would warm by an additional 0.5°C by 2100, a similar rise in temperature to that seen during the 20th century. In 2050, as much as 64% of that commitment would be due to ''past'' natural forcings (the result of previous human greenhouse gas emissions). Over time, their contribution compared to the human influence will diminish. Overall, the warming commitment at 2005 greenhouse gas levels could exceed 1°C.<ref>{{cite journal |last=Wigley |first=T. M. L. |title=The Climate Change Commitment |journal=Science |volume=307 |issue=5716 |pages=1766–9 |date=17 March 2005 |doi=10.1126/science.1103934 |pmid=15774756 |url=ftp://ftp.soest.hawaii.edu/coastal/Climate%20Articles/Wigley_2005%20Sea%20level%20commitment.pdf |format=PDF}}</ref> As ocean waters expand in response to this warming, global [[sea level]]s would mount by about 10 centimeters during that time. These models do not take into account [[ice cap]] and [[glacier]] melting; including those [[climate feedback]] effects would give a 1–1.5°C estimated temperature increase.<ref>{{cite web |url= http://www.nature.com/news/2005/050314/full/050314-13.html |title= Oceans extend effects of climate change |first=Deirdre |last=Lockwood |date= 2005-05-17 |work=Nature News |publisher= [[Nature Publishing Group]] |doi=10.1038/news050314-13}} </ref>
