Should the earth be warming naturally right now?

Question

Some people believe that human activity has little or no effect on present day climate changes. Their argument is that the planet has always had fluctuations in its climate, and the present rise in average temperature is just the latest normal fluctuation in planetary warming.

I heard somewhere that if you use past climate change patterns as a model for today's planetary warming, the planet should actually be going through a cooling period. If that is the case, does anyone have a scientific reference for that?

Answer 1

The warming is accelerated because of human activity.  The fluctuations prior to the industrial revolution were all due to natural factors.  Since the industrial revolution, natural and human factors are causing warming at a rate faster than any other time in history as far as we can tell.  I think figure 4 in this publication from the National Academy of Sciences is the comparison you want (look on page 7).

http://dels.nas.edu/dels/rpt_briefs/clim...

This is figure taken directly from the IPCC reports (I think working group 1).  The blue shaded are is the expected temperature change considering only natural factors while the reddish shaded area is the expected temperature change with natural and anthropogenic (man-made) factors

Answer 2

Yes the earth should be warming now as we are coming out of the Little Ice Age which ended around 1860. As far as going through a cold period (which we may already be), no one can predict the future climate (notice all models are wrong). But, if you look at the graph some interesting things are shown.

First, about every 100,000 to 120,000 years the earth rapidly warms after an ice age. Also, the previous warming has been much higher than our current warming. By studying the graph we can see that the warming spells seem to last around 20,000 to 30,000 years (I am eye balling the graph), then is followed by a rapid cooling phase. We are currently about 15,000 to 20,000 years into the current warming (who knows if it will start to cool now, or another 10,000 years from now). ONe other interesting point, notice how all the warm periods peaked, started a gradual slowing before temperatures really plummeted. Looking at our time period, it appears that the temps have already started a gradual decline. Let's hope we are not about to enter another glacial period. But if we do, you can bet your life savings that the same AGW proponents will still blame humans and demand we pay trillions of dollars to stop the cooling.

http://en.wikipedia.org/wiki/Image:Ice_A...

Answer 3

yes.

its in its warming stage

Answer 4

You can't predict the future based on the past.  End of story.  The past was the past, it won't necessarily repeat itself.

Answer 5

Actually the planet should be warming today.  Recent Temperature Time line

Roman Warm Period 0-450 AD

Migration Period Pessimum (Cold) 450-900 AD

Midievil warm period. 800-1300 AD

Little Ice Age 1250-1850

AGW 1850 - 2008

Look at the cycle you tell me.  The most interesting thing is that the Medieval warm period is about .5 deg C cooler today than it was in the IPCC 1995 report.  I need that one explained to me.

Truth is with a period 700 or so years ago warmer than to today fewer people will believe in AGW, so "We have to get rid of the midievil warm period."  and they did.  How 1000 AD dropped by over .5 deg C from 1995 to 2001 is beyond me.  Thank goodness all the scientists are smart enough to understand that.

Answer 6

There are no references because no one knows what the natural cycles would have resulted in without any influence from man.  Those that pretend to know are either ignorant of their own limitations or lying.   It is too complex of a system and there are too many variables that we don't know or understand well enough.

Answer 7

We actually were cooling slightly, for thousands of years.  This graph (references at end) shows that, and shows global warming changing it.  The graph is essentially a vertical line on the right hand edge.

http://www.globalwarmingart.com/wiki/Ima...

EDIT - The MWP is the little bump on the graph about 1000 years ago.  And the graph says it clearly was colder than today.

Answer 8

Absolutely.  The earth warms and cools in various cycles, some lasting 100 years or more.

And I've also heard it authoritatively reported that the actual warming we've been experiencing has amounted to a whole .7-degree -- not even a single degree.  But, of course, that's only in the last 20 or 30 years.  Pick a time during the 1800s and I bet we could find where average temps have actually dropped a degree or two.

Data and statistics can be molded to shape the cause -- and in this case (in my opinion) the cause was Al Gore's pocket book.  Has anyone actually checked to see where the cash for all those "carbon offsets" has ended up?

Answer 9

Yes, we should be warming right now regardless of CO2 because of the heightened levels of solar activity reached in the 50s--it takes centuries for the oceans to reach equilibrium with these high levels of solar activity. It is, however, difficult to quantify the sun's effect as aerosols and ocean circulations muddy the signal.

This is one of the reasons why the IPCC rates our understanding of solar influence on climate as "low".

Answer 10

To tell the truth the earth entered a cooling cycle late last year that might bring on a mini ice age that could last from 20 to 80 years. It might not be any worse than the one of the late 60s and early 70s that had the same lemmings calling for the next ice age that are now selling global warming. But it could be as bad as the one that ended the Viking settlement in Greenland.

Answer 11

So they accept the Mann Hockey Stick graph, but that link by Bob refutes the Hockey Stick Graph because Mann's graph shows the Medival Warm Period was colder than today.  But according to the Wiki graph Bob posted, the MWP was warmer than today.  Conflicting stories, as usual, from the supporting crowd.  This is the part of a debate I love, when a certain side floods the media outlets with information and it eventually contradicts all of the previous information.

The planet is starting a cooling period, ask NASA.  They just put out a story of how the PDO will cause cooling for the next 30 years.

The days are numbered for the global warming crowd, they contradict themselves and they have no proof besides .3 degrees of warming over the past 140+ years.

If you take the NASA base period of 1951-1980 (during a cooling era) and develop a standard deviation, you come up with -0.3 degrees.  So any chart listing 0.6 degrees of temperature rise should really state 0.3 degrees.  Simple when you know how to work with statistics.

EDIT-the graph says it was colder, but all of the research states that it was warmer.  The alarmists are trying to rewrite history to push their agenda.