3 replies to this topic

[Dingo]

I must say this is a revelation to me.

Quote

The key question in climate modeling is how much global warming you get from doubling CO₂, once all climate feedbacks are taken into account. A feedback is something that amplifies or cancels out the initial effect (eg. interest is a feedback on a loan). The models include “fast feedbacks” like water vapor, clouds, and sea ice, but exclude longer-term “slow feedbacks” like melting ice sheets (an icy surface reflects more heat than a dark surface).

Both models and paleoclimate studies agree the warming after fast feedbacks is around 3°C per doubling of CO₂. Slow feedbacks have received far less attention. Paleoclimate is the only available tool to estimate them. To cut a long story short, Hansen found the slow ice sheet feedback doubles the warming predicted by climate models (ie. 6°C per CO₂ doubling).

[still learning]

Dingo, on 18 June 2013 - 05:44 AM, said:

....this.....is a revelation to me....

More on the same subject here: http://www.realclima...itivity-part-i/

I think the Wikipedia entry on climate sensitivity is pretty good too: http://en.wikipedia....ate_sensitivity

If you want actual peer-reviewed journal articles on the subject, you might start looking here: http://www.columbia....lications.shtml

[Shortpoet-GTD]

From the article-
"If we do not act now, we could push the climate beyond tipping points, where the situation spirals out of control."

Some scientists said over 10 years ago that we had 10 years or less before we the tipping point would be
reached. I think many are too scared to face the fact that "tipping point" is in our rear view mirror.

I saw a small blurb on this on the evening news that should wake everyone up but it's another story
that went by the boards, unnoticed.

The Great Lakes water levels are dropping (have been for 15 years or so) and this fact goes unnoticed
and largely unreported on the national scene?

Everyone should be talking about this but instead it's.............crickets.

Reduced rainfall totals cannot keep up with the evaporation from the warming water.

That's a tipping point that no one talks about. Considering the size of these lakes, a two foot drop in level is a
lot of water.
"Changing weather patterns" my eye. That's part of it, but climate change is at the root of it.



"St. Mary's River, (the river connects Lake Superior to Lake Huron) is at record low levels.
Lake Superior also is low -- about a foot below its long-term average.
But Lake Michigan and Lake Huron are even lower, nearly two feet below their averages.
Their water levels have fallen for 15 years, the result of declining rainfall on the lakes, and increasing evaporation.
Source

And this piece from National Geographic.

"Each year, around 22 cubic miles of water evaporate off of Lakes Michigan and Huron.
That’s enough to cover the city of Chicago with 500 feet of water, or Washington, DC,
with 1,700 feet–three times the height of the Washington Monument!

We are very concerned about coastal wetlands that thrive in just a few feet of water.
The same lake level drop could easily dry up wetlands, which are critical habitats for migrating birds,
spawning fishes, and sensitive plants."
National Geographic article.

[Phil]

As the article rightly pointed out, nature will always adapt one way or another, it's we humans that are going to have to learn.  That means more drought proof yards, better water management, putting houses on stilts in flood prone area's, building levy's, dealing with warmer summers, colder winters, etc.  For me it meant moving as far north as possible without having to end every sentence with "eh"! :<O