There are reasons to assume that a linear fit is not smart.<p>If you assume the <i>rate</i> of melting is roughly proportional to the temperature, then we are in for an increase in rates.<p>But there are other things. Nonlinear ice effects - that are not very well included in IPCC projections, could cause a lot more sea level rise sooner. They are hard to predict.<p><a href="http:&#x2F;&#x2F;phys.org&#x2F;news&#x2F;2015-09-eyes-oceansjames-hansen-sea.html" rel="nofollow">http:&#x2F;&#x2F;phys.org&#x2F;news&#x2F;2015-09-eyes-oceansjames-hansen-sea.htm...</a>