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:
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.) 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)
<
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!
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 in the Arctic
The Arctic has been warming about 4 times faster than the rest of the world [since about 1990]:
The albedo effect is a positive feedback loop that plays a role in that faster Arctic warming:
Albedo effect
- A change (to Earth's temperature) happens: The average global temperature rises (Let's say, because of higher $CO_2$ levels),
- This causes more ice in the Arctic to melt than usual.
White ice mostly reflects light back into space. But darker water absorbs light energy, turning it into heat, - Because there is less ice and more water, more of the sun's energy is absorbed by the bare water near the North Pole.
- 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:
- A 100 degree day in Siberia (2020)
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.if (! $homepage){ $stylesheet="/~paulmr/class/comments.css"; if (file_exists("/home/httpd/html/cment/comments.h")){ include "/home/httpd/html/cment/comments.h"; } } ?>