‘Antarctic ice is growing’–Well, probably not, but even if it were, we are not off the hook
(Part of the How to Talk to a Global Warming Skeptic guide)
Objection: The Antarctic ice sheets are actually growing, which wouldn’t be happening if global warming were real.
Answer: There are two distinct problems with this argument.
First, any argument that tries to use a regional phenomenon to disprove a global trend is dead in the water. Anthropogenic global warming theory does not predict uniform warming throughout the globe. We need to assess the balance of the evidence.
In the case of this particular region, there is actually very little data about the changes in the ice sheets. The growth in the East Antarctic ice sheet indicated by some evidence is so small, and the evidence itself so uncertain, the sheet may well be shrinking.
But even this weak piece of evidence may no longer be current. Some recent results from NASA’s GRACE experiment, measuring the gravitational pull of the massive Antarctic ice sheets, have indicated that on the whole, ice mass is being lost.
Second, ice-sheet thickening is not inconsistent with warming! Warmer climates tend toward more precipitation. The Antarctic is one of the most extreme deserts on the planet. As it warms, we would expect it to receive more snow. But even a whopping warming of 20 degrees — say, from -50 degrees C to -30 degrees C — would still leave it below freezing, so the snow wouldn’t melt. Thus, an increase in ice mass.
While on the subject of ice sheets: Greenland is also growing ice in the center, for the same reasons described above. But it is melting on the exterior regions, on the whole losing approximately 200 km3 of ice annually, doubled from just a decade ago. This is a huge amount compared to changes in the Antarctic — around three orders of magnitude larger. So in terms of sea-level rise, any potential mitigation due to East Antarctic Ice Sheet growth is wiped out many times over by Greenland’s melting.
More stories in this series:
(Part of the How to Talk to a Climate Skeptic guide) Objection: In his June 23, 2008 testimony before the United States Congress, James Hansen called for the punishment of climate change skeptics for “crimes against humanity.” This is …
(Part of the How to Talk to a Climate Skeptic guide) Objection: In October 2008, Al Gore’s science adviser, James Hansen announced yet another “hottest” month on record. After all the alarmist banner headlines sank in, yet another “correction” quietly …
(Part of the How to Talk to a Climate Skeptic guide) Objection: We all live on a thin crust that floats on a huge ball of molten iron, and at its core, the Earth’s temperature is over 5000 degrees C! …
(Part of the How to Talk to a Climate Skeptic guide) Objection: Sea ice at the north pole recovered a whopping 9.4 percent from 2007 to 2008 despite the doom and gloom predictions of the alarmists. Yet another wheel falls …
Get Grist in your inbox