Climate of Man reading - part 1

1.) Graph the temperature as a function of depth as it looked a long time ago, and as it looks more recently.

2.) Is temperature in permafrost a better indicator of long term trends?

permafrost is not nearly as variable as the air temperature meaning that a change in a few degrees of the permafrost is a much more significant indicator of climate change and shows general trends rather than large amounts of fluctuations.

3.) Natural greenhouse effect?

57 F: Earth's average temperature with pre-industrial amounts of GHGs ("GreenHouse Gases"). There has been $CO_2$ in Earth's atmosphere for millenia before humans came along.

 0 F: Earth's average temperature with no GHGs. (Our climate has always had *some* $CO_2$ in it.)

4.) Feedback cycles

Ice reflects the light from the sun and as it melts and then when turned into water the water starts to absorb the heat. for example when you leave a water bottle in the sun the water... generally [becomes] very hot

- The albedo of the arctic is basically the light or the radiation of the sun that is reflected by any surface, so the more albedo, the better the surface will reflect radiation from the sun. Ice is the best reflector of the sun, but water is the worst reflector. If the ice gets exposed to water, then it will absorb more solar energy which refers to the heating of the ocean. As we melt the ice, we put more heat into it through the water which means that it will constantly heat up more and more and the ice will melt down faster and faster. This is one of the major reason that the Arctic is warming so rapidly.

Anything that changes the albedo changes how much energy the planet absorbs. Water [...] absorbs more solar energy [than ice], heating the oceans. So if the ice caps and permafrost melt and turn into water due to climate change, it allows even more solar energy to be absorbed, and will make earth a lot warmer a lot faster.

It's amazing and also a little scary how there is such a big spiral effect that surround[s] global warming and greenhouse gases. When humans create CO2, the earth warms which melts glaciers and warms the ground. This causes the ground to release even more CO2 into the atmosphere which leads to even more warming and melting. This cycle or spiral is very concerning [...]

As snow melts on the ice sheets it increases the flow of ice towards the ocean where ... the sheet is melted into the water. Since this occurs at a faster rate than the snow can reform the ice it gets worse every year as the cycle speeds up.

Overall impressions

scientists have been working on finding the reason for global warming and the greenhouse gases and its effect since decades ago.

The story gave the readers a personal connection to the over-b earing stats that are usually written about in an article covering climate change and global warming.

Why is this not being talked about more[?] Yes, global warming is talked about a lot but things are rarely ever done about it...

The Ozone hole

Yes, there has been a thinning of Earth's ozone layer. It's particularly acute over Antarctica, and thus we call it a "hole". But there is somewhat less ozone all over Earth.

The same chemicals (Chlorofluorocarbons - CFCs) that destroyed atmospheric ozone are also potent GHGs.

The main concern about loss of ozone is the increased amount of UV light from the sun that makes it through Earth's atmosphere. This can lead to:

• Increased skin cancers
• Increased cataracts
• Increased death of Antarctic plankton--food source at the bottom of the Antarctic food chain

But "ozone depletion is not a major cause of climate change" [NOAA].