question: how to answer the meme about natural warming cycles

[unpossibles]

From a discussion on another board:

Global Warming is a FACT.

...and it is happening because it is SUPPOSED TO.

We are receeding from an Ice Age. The glaciers are supposed to be melting.

the earth has gone through at least half a dozen warming-cooling cycles....and we are not going to change that.

here's the last one:

Paleocene Epoch
65-55 million years ago During the Paleocene, the vast inland seas of the Cretaceous Period dry up, exposing large land areas in North America and Eurasia. Australia begins to separate from Antarctica, and Greenland splits from North America. A remnant Tethys Sea persists in the equatorial region.

Eocene Epoch
55-34 million years ago Plate tectonics and volcanic activity form the Rockies in western North America. Erosion fills basins. Continental collisions between India and Asia culminate in the Alpine-Himalayan mountain system. Antarctica and Australia continue to separate and drift apart.
The climate is subtropical and moist throughout North America and Europe.

Oligocene Epoch
34-24 million years ago Tectonic plate movement is still very dynamic. Africa and Europe nearly collide, closing the Tethys Sea and leaving as a remnant the Mediterranean Sea. Volcanism and fragmentation of western North America is associated with the emplacement of major ore deposits.
The southeren ocean forms and the climate is generally temperate. Glaciation begins in Antarctica.

Miocene Epoch
24-5 million years ago Modern ocean currents are essentially established. A drop in sea level near the end of the Epoch isolates and dries up the Mediterranean Sea, leaving evaporite deposits on its floor.
The climate is generally cooler than the Oligocene Epoch. A cold transantarctic ocean current isolates the waters around Antarctica, and the continent becomes permanently frozen.

Pliocene Epoch
5-1.8 million years ago The emergence of the Isthmus of Panama changes ocean circulation patterns and coincides with the formation of an Arctic ice cap. Plate tectonic interactions result in the uplift of the Sierra Nevada, formation of the Cascade Range, and onset of strike-slip faulting on the San Andreas Fault. In Europe, the Alps continue to rise.
The global climates become cooler and drier.

Pleistocene Epoch
1.8 million-10,000 years ago This epoch is best known as the "Great Ice Age." Ice sheets and other glaciers encroach and retreat during four or five primary glacial periods. At its peak, as much as 30% of the Earth's surface is covered by glaciers, and parts of the northern oceans are frozen. The movement of the glaciers alters the landscape. Lakes, such as the Great Lakes in North America, are formed as ice sheets melt, and retreat. Global warming begins after the last glacial maximum, 18,000 years ago.

Holocene Epoch
10,000 years ago to the present
The Holocene Epoch may be an interval between glacial incursions, typical of the Pleistocene Epoch and therefore not a separate epoch in itself. However, it is a period marked by the presence and influence of Homo sapiens. During this time, the glaciers retreat, sea levels rise, the climate warms, and deserts form in some areas.

Personally, I would agree that there are natural cycles, but that we are accellerating the problems.

I just thought I'd ask here and see what people thought. To me the time period of the previous periods, versus the modern one would seem to be a hint. Also, I feel that I don't understand why it would be a bad idea to try to live more cleanly on renewable fuels, even if Global Warming is 100% natural.

[phantom power]

1. It's been dealt with here:

www.realclimate.org

The "answer" is that the data still shows warming when "natural cycles" are taken into account. And, well, every climate scientist has concluded it's happening, and anthropogenic GHGs are responsible.

Of course, there are plenty of details to argue about, but there is no longer any debate about whether it's happening. That debate ended years ago, except among certain very powerful corporations and politicians who have a vested interest in keeping the "debate" on artificial life support.

[unpossibles]

5. thanks! and to everyone else for the fast response

that was my feeling about it - and I even have a few friends who do some climate/envionmental research, just wanted to get some opinions.

What I told him was essentially the same, although the link is a good thing to have.

What's interesting is, the guy is smart and a good person, pretty Left, but finds problems with this issue because of religious reasons, in my opinion. I know it sounds silly, but based on past conversations with him, I think he has trouble thinking that mankind could make a permanent effect on God's creation. He's kind of an enigma in that he has a scientific education and believes in evolution, yet can also be a Biblical literalist. We have pretty good discussions about these things, but I admit I'm not sure how to wrap my brain around that one.

I don't know, and I'm not sure I could convince him otherwise if he chooses to ignore the data.

[tridim]

2. It doesn't matter who or what caused it

We still need to do everything in our power to stop and/or reverse the trend.

[hatrack]

3. Apples and oranges

What we're seeing is change at a pace exceeding all of the warming phases listed here and associated with large-scale geological shifts.

What this poster is talking about is geological movements taking place over tens of millions of years and the concomitant climate shifts.

What we're seeing is change moving at speeds which are multiple orders of magnitude faster than any which went before - ten times or 100 times faster than any of the long-term shifts listed in the post you cite.

[skids]

4. a) The rate of change is unnatural and b) ocean acidification

First off, only company shills think that warming is 100% natural. Practically everyone else who has any expertise has already heard this idea and is still convinced that a large portion of the warming is manmade.

Secondly, if they want to bring pre-history into the argument, they may note that in those cases where the earth's climate changed rapidly, mass extinction events occurred. The problem isn't so much that the earth is warming, it's how fast. Biological systems need tens of thousands of years to properly adjust -- if they are exposed to rapid change we get dieoff, and we won't escape being part of that dieoff due to its impact on the food supply. Even if our activity isn't bad enough to do this on its own, which is arguable, it is threatening to instigate a catastrophic methane release from permafrost and deep ocean clathrates -- we are just the trigger.

Heck, even if it were naturally caused we should still fight it: if a planet-killer meteor was heading towards the earth would they suggest we should do nothing because meteors come from "natural causes"?

Thirdly, even if they stick their head in the sand and just will not admit to the dangers of warming, they still haven't dealt with the problem of ocean acidification, where we are killing the ocean's foodchains by force-feeding it atmospheric CO2. That's another way that burning fossil fuels is threatening the global food supply, and it has nothing to do with the planet warming.