Dr. Kiki's Science Hour 2

Dr. Kiki's Science Hour Episode 2

Guests

Michael Wehner, scientist at Lawrence Berkeley National Labs. Works in the computational science division on climate models. Recently wrote paper in Geophysical Review Letters about how we should looking at and talking about data on global climate change. ("Is the climate warming or cooling?" Geophysical Research Letters, Vol. 36, No. 8, 25 April 2009)

Climate Science

How to look at, model, and talk about climate data and global climate change.

Dr. Wehner gives a wonderfully clear overview of how he and his colleagues, as climate scientists, look for the fingerprint of human-induced global climate change. A rich conversation follows.

• They looked at the last 108 years and in the last 10 years there isn't a lot of warming as 1998 was a warm year and it skews the results

• There are two questions?
  • Is climate change happening ?
  • What is the cause?

• You also have to ask what will happen in the future
• This is hard to predict as you need to know what people are going to do in the future

They natural causes they measure are:

• Solar activity
• Volcanic Activity

• Sceptics will claim it is all due to the sun
• If this was true then the atmosphere would be warmed evenly but this is not the case
• The lower atmosphere is warming and the stratosphere has cooled

• When he first started looking at climate change they only measured surface temperature
• They were criticised for this as if climate change was occurring more would change than the surface temperature
• Precipitation patterns would also change

So in the last 7 years they have looked at:

• The lower troposphere
• The stratosphere
• The distribution of moisture in the atmosphere (If the climate is warming there will be more moisture in the atmosphere)
  • This is very easy and accurate to measure with satellites
• The temperature of the oceans

Question: The planet will solve the problem itself why do we need to get involved?

Answer: The rate at which climate changing is occurring is increasing. The planet has been shown to be able to adapt to change over long periods of time not decades. Hurricanes will also get stronger which is dangerous for humans.

• We are taking carbon that has been trapped in the earth and releasing it back into the atmosphere by burning fossil fuels

Question: How accurate are your models?

Answer: The models are good for some things and not others. You cant just take the raw output though and not think about what it says. As computers get more powerful the models will become more specific

Question: Is a new Ice Age Coming?

Answer: If you make claims like that you need proof and no one has it

The null hypothesis is that there is no warming and we can reject it with over 95% significance

Question: What about the claims that the oceans are not warming?

Answer: The time period those measurements where taken over is too small

• There was drop in the surface air temperature right after the second world war
• The sea ice is thinning but this does not raise sea levels

Question: What should we teach children about climate change ?

Answer: Keep an open mind and learn more about it

• The climate has been changing for longer than humans have been here
  • The rate of change is increasing though

• The effect of increased carbon is self limiting
  • There is no evidence to suggest this

• The solar cycle has a bigger effect on the climate than all human activity
  • This is not true

• This a politically motivated scam
  • This makes no sense why would people conspire to prove the earth is warming. The conspiracy if any would be oil companies trying to prove the earth isn't warming

Recommended Links

International Panel on Climate Change: Read the executive summary of the working group

US Global Change Research Program; (site's URL changed from climatescience.gov): a good site with good information

Climate Experts Warn that Short-Term Snapshots of Temperature Data Can Be Misleading: Focus Instead on the Bigger Picture

Notable Quotes

"If you make extraordinary claims, you've gotta have extraordinary proof. We've made extraordinary claims, and we have extraordinary proof." -- Michael Wehner

Production Information

• Recorded Date: May 7, 2009
• Release Date: May 7, 2009
• Duration: 1:25:15
• Log line:
• Edited by:
• Notes: Jason E Miller

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