Question: What tells you how the ice is melting?

Octavia Brayley answered on 13 Nov 2023:

Thank you for your great question! There are lots of bits of evidence to show ice melt. For example, scientists often use ice cores to analyse past climates. They drill into the ice and obtain these long cores and then they analyze different chemical components (like isotopes) and electrical conductivity (and other things- but I’m not an expert!) and they can use this to build up a record of paleoclimate, or the history of climate. They have shown that although past climate has fluctuated throughout history, global warming is happening at a faster rate now than it ever has in history. Earth observation satellites are also key to monitoring the polar ice because they carry instruments that measure changes in the thickness of the ice sheets, fluctuations in the speed of the outlet glaciers, and even small changes in Earth’s gravity field caused by melting ice. Scientists working in Antarctica have also actually seen big bits of ice falling off from glaciers into the water. Over time, we will also see a rise in sea levels. There’s an enormous ice sheet in Western Antarctica, and if it continues to melt at current rates, we predict to see a 3-metre rise in global sea levels in the next 200 years. These predictions are made by computers and modelling. Below are some videos to give you some more information about these ideas.