Is Global Warming real?

[Dannyalcatraz]

In essence, I accept that we have taken a slow, natural warming process, that the planet is currently undergoing, and artificially ramped it up to geologically breakneck speeds. Subsequently, changes are occuring at a far greater pace than the environment, and nature, are capable of adjusting to. This makes the current warming cycle 'unnatural' in nature.

...except we are not in a natural warming cycle, we're in a natural cooling cycle...but we're still warming.

Where are we currently in the natural cycle (Milankovitch cycle)? The warmest point of the last cycle was around 10,000 years ago, at the peak of the Holocene. Since then, there has been an overall cooling trend, consistent with a continuation of the natural cycle, and this cooling would continue for thousands of years into the future if all else remained the same. But since 1750 however, the CO2 content of the atmosphere has deviated from the natural cycle. Instead of decreasing, it has increased because of the fossil-fuel burning. Methane and nitrous oxide have also increased unnaturally because of agricultural practices and other factors. The world has also warmed unnaturally. We are now deviating from the natural cycle.

http://ossfoundation.us/projects/environment/global-warming/natural-cycle

For example, we are warming far too fast to be coming out of the last ice age, and the Milankovitch cycles that drive glaciation show that we should be, in fact, very slowly going into a new ice age (but anthropogenic warming is virtually certain to offset that influence).

The "1500-year cycle" that S. Fred Singer attributes warming to is, in fact, a change in distribution of thermal energy between the poles, not a net increase in global temperature, which is what we observe now.

The Little Ice Age following the Medieval Warm Period ended due to a slight increase in solar output (changes in both thermohaline circulation and volcanic activity also contributed), but that increase has since reversed, and global temperature and solar activity are now going in opposite directions. This also explains why the 11-year solar cycle could not be causing global warming.

http://www.skepticalscience.com/global-warming-natural-cycle.htm

 

[was]

...except we are not in a natural warming cycle, we're in a natural cooling cycle...but we're still warming.

Do you have a good source on this? It's my understanding that we have been warming since the end of the Pleistocene (11000-12000 years ago) with the end of the last ice age/glacial retreat.

 

[Dannyalcatraz]

Edited in while you were posting.

 

[was]

Edited in while you were posting.

Sorry, a bad internet connection, late night posts and awful spelling lead to me editing/taking a long time on my posts.

I'm perusing the listed links but I have never heard of these authors/agencies. Are there any leads to a more well-known source? It's so hard to tell who's legit anymore on the web.

 

[Dannyalcatraz]

Well, NASA.
http://earthobservatory.nasa.gov/Features/GISSTemperature/giss_temperature2.php

http://earthobservatory.nasa.gov/Features/GlobalWarming/page4.php

Even though the 2000s witnessed a solar output decline resulting in an unusually deep solar minimum in 2007-2009, surface temperatures continue to increase.

http://climate.nasa.gov/evidence/

The EPA

Changes in solar energy continue to affect climate. However, solar activity has been relatively constant, aside from the 11-year cycle, since the mid-20th century and therefore does not explain the recent warming of Earth. Similarly, changes in the shape of Earth’s orbit as well as the tilt and position of Earth’s axis affect temperature on relatively long timescales (tens of thousands of years), and therefore cannot explain the recent warming.

http://www.epa.gov/climatechange/science/causes.html

 

[Ryujin]

With respect to opinions, not all of them are equal. Here's an example of one of the "foremost Canadian climate change deniers"; Tomothy Ball. Note the issue regarding his credentials.

http://www.sourcewatch.org/index.php/Tim_Ball

 

[Umbran]

Do you have a good source on this? It's my understanding that we have been warming since the end of the Pleistocene (11000-12000 years ago) with the end of the last ice age/glacial retreat.

We can start here: https://en.wikipedia.org/wiki/Ice_age

Specifically, with this graphic, which shows the pattern of temperature over time for glacial periods, as well as CO2 and dust concentrations for the same times:

https://en.wikipedia.org/wiki/Ice_age#/media/File:Vostok_Petit_data.svg

Let me see if I can attach that:


The 0 of time at the right is the present, and time goes farther back into the past as we go further left. The end of the last glacial period is the low near the right end of the graph.

In this, we can see that "warming since the end of the glacial age" is not the usual pattern. A glacial period ends in a sharp snap of rising temperature, and then an overall slow cooling down into the next glacial period. We had the sharp rise some 11,000 years ago or so, and we should have been in a cooling trend into the next glaciation period.

We can see, in fact, that our current temperatures are near the highest we typically get for the current epoch. For the past 400,000 years or so, Earth has been spending most of its tie much cooler than it is right now, not warmer.

 

[Kramodlog]

I have a question for climate skeptics.

What would you need to be convinced of global warming and that it is a serious matter that affects us?

 

[Umbran]

We should note an ambiguity of terminology. Specifically, "Ice Age".

From a paleoclimatological/geological sense, there have been 5 Ice Ages - periods that can have significant glaciation on the planet. The two first Ice Ages may well have had the planet *entirely* covered in ice (a "snowball earth"). But generally, within an Ice Age, there are several periods of glaciation followed by inter-glacial periods. From this standpoint, we are in an ice age, during an inter-glacial period. When you leave an Ice Age, there is no more extensive glaciation anywhere on the planet - including the poles.

Colloquially, we refer to any glaciation period as an ice age.

 

[Janx]

I have a question for climate skeptics.

What would you need to be convinced of global warming and that it is a serious matter that affects us?

probably an education in how to read that graph.