Climate of Man assignment

Rest in peace Konrad Steffen

1.) Graph the temperature vs depth (Romanovsky)

...as it was several decades ago, and more recently


Even better: Draw the two curves on the same graph, to show that deep down the temperature profile is still the same. But the closer you get to the surface, the recent graph gets warmer and warmer compared to the older profile:

Were you surprised that temperatures go up as you go down? The temperature at the lower depths of the Mponeng gold mine (S Africa) reaches 140 ${}^\circ$F.

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

[Yes,] because it reacts more slowly to temperature variations compared to air
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.) Earth's average temperature

Scientists estimate (NASA) that the "natural greenhouse effect" is the reason why the average temperature on Earth is about 59F today. (Kolbert said 57 F with "pre-industrial" levels of greenhouse gases (GHGs)

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If there were no greenhouse gases in Earth's atmosphere, Earth's average temperature (NASA-GISS) would be closer to 0F.

Thank goodness for the natural greenhouse effect!


NASA, Earth Observatory 1750-2008, atmospheric levels of $CO_2$ and methane.

Natural greenhouse effect 57 F with pre-industrial levels of 280 ppm $CO_2$.

Enhanced greenhouse effect is the *additional* warming caused by humans, anthropogenic warming, since we've been dumping additional amounts of long-lasting greenhouse gases into our atmosphere. 2019 $CO_2$ level of 410 ppm.

The last time there was this much $CO_2$ in Earth's atmosphere was 800,000 years ago.

Now, one of the biggest challenges of our generation...

Warming and feedback in the Arctic - Albedo effect

The Arctic has been warming about 4 times faster than the rest of the world [since about 1990]:

Robert Rhode

The albedo effect is a positive feedback loop that plays a role in that faster Arctic warming:

The Arctic is heating more rapidly in large part because of a feedback loop in which warming melts sea ice in the region, which exposes more of the Arctic Ocean to sunlight and leads to more warming, which in turn leads to even more melting and warming. The result of this and other oceanic and atmospheric processes is called Arctic amplification.

Arctic Warming Is Happening Faster Than Described, Analysis Shows NYTimes, 2022

Albedo effect

  1. A change (to Earth's temperature) happens: The average global temperature rises (Let's say, because of higher $CO_2$ levels),
  2. This causes more ice in the Arctic to melt than usual.


    TES solutions teaching resources.
    White ice mostly reflects light back into space. But darker water absorbs light energy, turning it into heat,

  3. Because there is less ice and more water, more of the sun's energy is absorbed by the bare water near the North Pole.
  4. So, the overall global temperature goes up even further, [causing even more ice to melt, causing the ocean to absorb yet more sunlight each year...]

Positive feedback: A change happens. [Less ice because of higher temperatures]. This causes a change in the system. That change acts to further *magnify* the original change.

Basically we get into this vicious cycle that continues to feed upon itself.

See also:

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-bearing stats that are usually written about in an article covering climate change and global warming.