(Part of the How to Talk to a Global Warming Skeptic guide)
Objection: Climate has always changed. Why are we worried now, and why does it have to be humans' fault?
Answer: Yes, climate has varied in the past, for many different reasons, some better understood than others. Present-day climate change is well understood, and different. Noting that something happened before without humans does not demonstrate that humans are not causing it today.
For example, we see in ice core records from Antarctica and Greenland that the world cycled in and out of glacial periods over 120Kyr cycles. That climate cycle's timing is fairly well understood to be caused by changes in the orbit of the earth, though the mechanism behind the response has not been conclusively established. These orbital cycles are regular and predictable and they are definitely not the cause of today's warming. The other important difference between the glacial-interglacial cycles and today is the rapidity of the current change. The rate of warming is on the order of 10 times faster today than in the ice cores.
Such rapid warming on a global scale is quite rare in the geological record, and while it may not be entirely unprecedented, there is strong evidence that whenever such a change has happened, whatever the cause, it was a catastrophic event for the biosphere.
Skeptics claim global warming is fake after top scientists’ emails hacked at CRU
Comments
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sunflower Posted 3:46 am
21 Dec 2006
Something just leaps off the page... that the Earth's climate is highly sensitive to CO2, far more sensitive than the wobbles of Earth's orbits around the sun. The theory is that ice covers rock, restricting CO2 removal, causing a CO2 buildup, which eventually ends the ice age with global warming caused by CO2. The ice melts, the exposed rock absorbs some CO2, and the cycle starts over again.
By definition, we are still in an ice age (a hot ice age) because of ice in the Antarctic, the Arctic, and Greenland. Once this ice melts (rapidly) the exposed rock will accelerate CO2 removal (requires a very very long time). Other big influences include continental shift, ocean currents, and albedo.
I now better understand the panic of scientists. The amount of CO2 humans generate far exceeds the CO2 embodied in these sensitive cycles. The expected increase in anthropogenic CO2 will cook the Earth far beyond the level at which life (as we know it) can survive.
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wiscidea Posted 4:52 am
21 Dec 2006
In the past, as seal levels rose and fell... as ice retreated and advanced... as deserts expanded and contracted... it was possible for our ancestors -- from primitive shrews to modern humans -- to move with the shifting environment. But now, it is a bit more crowded. Non-human animals are confined to fragmented habitat and do not even have safe corridors to move through from one region to another. And humans -- in case you did not notice -- pretty much occupy or at least lay claim to most of the Earth's surface. Where do you, Mr. Global Warming Skeptic, plan to go if your home becomes surrounded by desert or submerged by salt water? And, Mr Global Warming Skeptic, how are you going to handle 100s of thousand of refugees when they show up in your neck of the woods because there is nowhere else for them to go.
The CONSERVATIVE thing to do is to preserve the climate we have and understand, the climate we can grow food in, the climate our various nations developed in.. unless you do not mind yourself or your decendents perishing. Afterall, just like the climate is always changing, species are always going extinct.
That is what I have to say to Mr. Global Warming Skeptic.
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Eleanor Posted 10:12 am
21 Dec 2006
Energy no matter how it is created is never "free". There is always some consequence. As wind farms lead to greater profits, greed will take precedence over environmental concerns.
Where is the discussion of energy conservation? If this country focused on cutting back our consumption of energy we wouldn't need to build so many wind farms.
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Laurence Aurbach Posted 5:56 am
22 Dec 2006
Risk Management Solutions, a company that forecasts the risk of natural disasters for the insurance industry, changed its computer modeling this year and predicted that more hurricanes would make landfall over the next five years. That means annual insurance losses could increase by up to 30 percent in the mid-Atlantic and Northeast, and 50 percent in the Gulf, Florida and the Southeast, the company said.
There is debate over whether the cause is global warming or a natural warming cycle. The National Association of Insurance Commissioners set up a task force to study climate change.
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solman Posted 5:25 pm
15 Mar 2007
You say "Noting that something happened before without humans does not demonstrate that humans are not causing it today."
That helps you argue with somebody who believes that they can "prove" that global warming isn't happening.
It hurts against a personal who is skeptical of global warming because it reminds us that historical data that supports a hypothesis is not sufficient to prove it.
I consider myself to be more of a skeptic, but I have become fairly convinced of the anthropogenic component of global warming because of the RAPIDITY of the current warming trend. I'd consider leading with something like:
"Although the planet has warmed before, it has never warmed on anything approaching the time scale of the current global warming phenomenon."
and give specific numbers and data to support that.
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