A 2014 peer-reviewed paper in the scientific journal The Cryosphere finds global glaciers melted at the same rate in the first half of the 20th century as in the second half. As explained in the blog The Hockey Schtick:
This implies no man-made influence on glacier melt, since the melting began naturally at the end of the Little Ice Age in 1850 with “safe” CO2 levels, and continued at the same rate throughout the 20th century with no acceleration. The authors predict glacier mass loss will continue at the same rate in the 21st century and have “relatively weak dependence” on future greenhouse gas emissions.
Since glacier mass loss is the largest single cause of sea level rise, this explains why there has been no acceleration of sea level rise over the past 100-200 years and why sea level rise is also unlikely to accelerate in the 21st century.
The lack of any acceleration in glacier mass loss and sea level rise in the 20th century despite an exponential rise in greenhouse gases proves that both of these processes are primarily natural and unrelated to CO2.During prior interglacials, most glaciers disappeared, as well as the entire ice sheet of Greenland and West Antarctica, all entirely natural and with “safe” levels of CO2. There is no evidence the current interglacial is any different.