Global warming compared to past cycles of history...?

Question

i just got into a debate with someone over past cycles of the earth and recent global warming...does anyone know of any RELIABLE websites that talk about the differences in natural global warming cycles and the current trend of global warming?

Answer 1

While it is undoubtedly true that there are natural cycles and variations in global climate, those who insist that current warming is purely natural -- or even mostly natural -- have two challenges.

First, they need to identify the mechanism behind this alleged natural cycle. Absent a forcing of some sort, there will be no change in global energy balance. The balance is changing, so natural or otherwise, we need to find this mysterious cause.

Second, they need to come up with an explanation for why a 35% increase in the second most important greenhouse gas does not affect the global temperature. Theory predicts temperature will rise given an enhanced greenhouse effect, so how or why is it not happening?

The mainstream climate science community has provided a well-developed, internally consistent theory that accounts for the effects we are now observing. It provides explanations and makes predictions. Where is the skeptic community's model or theory whereby CO2 does not affect the temperature? Where is the evidence of some other natural forcing, like the Milankovich cycles that controlled the ice ages (a fine historical example of a dramatic and regular climate cycle that can be read in the ice core records taken both in Greenland and in the Antarctic)?

Is this graph a candidate for explaining today's warming? A naive reading of this cycle indicates we should be experiencing a cooling trend now -- and indeed we were gradually cooling over the length of the pre-industrial Holocene, around .5C averaged over 8,000 years.

Not only is the direction of the change wrong, but compare the speed of those fluctuations to today's changes. Leaving aside the descents into glaciation, which were much more gradual, the sudden (geologically speaking) jumps up in temperature every ~100,000 years represent a rate of change roughly ten times slower what we are currently witnessing.

So could current changes be part of a natural cycle? Well, no natural cause has been identified. There is no climatological theory in which CO2 does not drive temperature. And natural cycle precedents do not exhibit the same extreme changes we're now witnessing.

In short: No.

For story: 'Current global warming is just part of a natural cycle'

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Climate sensitivity to CO2

CO2 is about 1/3 of one percent of air.  Without CO2, the earth would be minus 18 C.  Obviously CO2 is a powerful greenhouse gas.

The planet Venus is hotter than the planet Mercury, even though Mercury is closer to the sun.  Venus is hotter because her atmosphere contains more CO2.

The earth has gone through many cycles of warming and cooling.  As CO2 levels shoot up, so do temperatures.  Carbon is both removed from the air, and added to the air by nature.  Sometimes, this carbon balance is upset by volcanic activity, a meteor impact, or more/less heat from the sun.

As the earth warms, carbon sinks (like forests, the permafrost, or the sea floor) become carbon emitters big time.  CO2 and methane flood the atmosphere and overwhelm the carbon eco-system.  For instance, 55 million years ago a natural runaway global warming episode (nicknamed the PETM) caused mass extinctions.  About 500 million years ago the global warming episode was so bad that most life died (that's why it was nicknamed the "Great Dying).

Mankind is triggering the same kind of severe runaway global warming episode by releasing tremendous amounts of greenhouse gas mainly by burning fossil fuels.  Do we really want to trigger another "natural" episode of severe warming?  Extinctions are natural, but do we want to cause another?

One final note:  I think that our climate is more sensitive to CO2 increases than is currently commonly understood by science.  Positive feedback loops (where a little warming causes carbon sinks to become carbon emitters, leading to larger warming) are not currently included in most climate models.  Particularly, the melting of methane hydrate in permafrost and under the ocean.

Answer 2

Nation Academy of Sciences

NASA

Answer 3

These are called Milankovitch Cycles. You can look them up.

At no time in the past 650,000 years has CO2 increased to levels we are at today. Thank God, the system is dynamic.

Today here is what we know:  many of mankind’s advancements cause earth surface to warm, destroy the ozone layer, kill off endanger species, heat cities, and in some way cause more destruction.  Blacktop (roads and parking lots), buildings, air pollution (causes lung and other diseases), deforestation, duststorms (which increase hurricanes and cyclones and cause lung diseases), fires (cause pollution, mud slides, and deforestation), refrigerants (like CFC's), solvents (including benzene destroy the ozone layer raising skin cancer rates) and plastics; cars, airplanes, ships and most electricity production (causes pollution including raised CO2 levels) are human problems we need to fix to keep life on earth sustainable! The federal government needs to adopt a pollution surcharge to balance the field and advance new technologies. We must pay the real price of oil (petrochemicals) including global warming, cleanup and for health effects. But with that we must understand we have never seen what is now happening before. CO2 has never lead to temperature change, but temperature change has led to increases in CO2. The models have to be made as we go along with little evidence! The result is:  change is on the way, we just do not know what changes. But again adding a small amount of CO2 to the atmosphere enlarges the earths sun collection causing warming; increase water in the atmosphere and they form clouds cooling earth but causing flooding. Even natural events are warming earth and causing destruction. The sun has an increased magnetic field causing increases in earthquakes (more destruction), volcanoes (wow, great destruction), and sun spots. Lighting produces ozone near the surface (raising air pollution levels). But humans have destroyed half of the wetlands, cut down nearly half of the rain forest, and advance on the earths grasslands while advancing desertification which increases duststorms. The USA Mayor's have taken a stand and I believe are on the right track, we can have control and can have economic growth. With the peak of oil in the 1970’s, the peak of ocean fishing in the 1980’s, humans must stop procrastinating and make real changes to keep earth sustainable including in the energy debate, finance and regulation. The sun is available to produce energy, bring light to buildings and makes most of human’s fresh water. Composting is the answer to desertification. New dams are the answer to fresh water storage, energy and cooling earth by evaporation, we need many small ones all over (California needs 100 by 2012 and has not even started).

President Bush has made a choice of energy (ethanol) over food and feeding the starving people around the world; this is a choice China has rejected.

That is why I founded CoolingEarth.org, a geoengineering web sight where you can learn more about earth, the atmosphere, and how to sustain life on earth’s surface.

Answer 4

a ice berg which was alive for millions of years have been melted recently due to the increasing temperatures....

the temp increase made a lot of forest fires in USA and Australian countries...

large number of floods in all parts of the world...

polar bears have been striving for their lives...

in Antarctica, where we think no one lives has been a place for we to produce electricity and leave out the exhaust directly into the atmosphere...

new thing - ocean foam in Australia..

what are these things..

also do u know that the warmest years were only recorded in the last decades..

then too many coast lying regions will disappear in the forthcoming years..

Florida going to vanish one day..

Maldives going to be in the sea....