Should you be a Global Warming skeptic?

* AGW is the theory that mankind is causing the planet's temperature to increase, due to our burning of carbon-based fuels.

What an intelligent non-scientist needs to know about Anthropogenic Global Warming (AGW)*

Borepatch [at] gmail [dot] com

Yes

This is the Cliff Notes answer.

Of course, that isn't much help.

The rest of this is about why you should be a skeptic, and why that's A Good Thing.

Is the climate changing?

Yes. We know from the historical record that has

changed several times over the last 1000 years, in a major way.

You are

here

1000 AD

Medieval Warm Period

Little Ice Age

1066 and all that

Image credit: Wikimedia. Public Domain picture.

The Domesday Book – 1086Who owns can be taxed for what?

Image: UK National Archiveshttp://www.nationalarchives.gov.uk/domesday/discover-domesday/great-domesday.htm

Image credit: Agne27, via Wikimedia.Licensed under Creative Commons Attribution 2.0

Dozens of vinyards in England in 1086.

982 AD – Eric the Red discovers Greenland

Who would start a colony on a glacier?

Especially with Vikings? They'll kill you ...

Image credit: Wikimedia user Wikid77.Licensed under Creative Commons ShareAlike 2.5

Image credit: Wikimedia user Pinpin. Licensed under the GNU Free Documentation 1.2

Harvests were goodEnough food surplus to build Cathedrals

Image credit: Linda Howser

Image credit: Wikimedia. Public Domain picture.

The Little Ice AgeAround 1350 AD to 1850 AD

We know from the historicalrecord that it got much colderstarting around 1300 AD.

In a pre-industrial society, you'renever more than two badharvests from disaster.

Within two generations, one-third of the population betweenthe Indus River and Iceland died.

Pieter Breugel the Elder, 1601 ADWinterlandschaft mit VogelfalleImage from Wikimedia Commons

The Little Ice AgeGreenland Vikings starved to death

Image credit: Frederik Carl Peter Rüttel via Wikimedia. Public Domain picture.

Every Man, woman, and child.

They even ate their dogs.

But they starved to death anyway.

Jared Diamond tells their story.

The Little Ice AgeHans Brinker and the Silver Skates

Remember the story of Hans Brinker and the Silver Skates?

Try skating on brakish Dutch canals today.

Good think Hans lived during the Little Ice Age.

Except for that bit with his Dad's brain surgery.

Image credit: Théophile Schuler via Wikimedia. Public Domain picture.

The Little Ice AgeThe American Revolution

Ethan Allan's Green Mountain Boys dragged captured british cannon from Ft. Ticonderoga to Boston over frozen rivers.

Image credit:Heppenheimer & Maurer via Wikimedia. Public Domain picture.

Thermometers – gimme data!It's been getting warmer

The thermometer was invented in the early 17th Century.

The oldest continuous temperature data record seems to be from Central England, and dates to around 1650 AD.

By the 18th Century, we had modern temperature scales:

1724 – Fahrenheit 1742 – Celsius

It's clear from the temperature records that it's been warming ever since we had thermometers, at least up until around 1940.

Image credit: Luis Miguel Orta Rial, via Wikimedia.Licensed under Creative Commons Attribution 3.0 Unported

Reason #1 to be (scientifically) skeptical about AGW

We know that climate changes.

We know that it's been warm in the past – as warm or warmer than today.

We know that it got cold in the not so distant past – much colder than today.

We know that it's been getting warmer for at least 300 years, probably longer.

It's not clear how burning fossil fuels starting in 1850 explains this.

If we only have 300 years of thermometer records, how to we know what the temperature was in 1000 AD?

Scientisits use ”proxies” - things that react to temperature, and that we can measure.

Trees typically grow faster when it's warm, and slower when it's cold. The width of the tree rings is a proxy.

Glaciers will get more snow and ice in cold years than in warm years. The width of layers in a core drilled from a glacier is a proxy.

Thermometer invented

Image credit: National Science Foundation, via Wikimedia. Public Domain image.

Image credit: Wikimedia user Arnoldius.Licensed under Creative Commons Attribution

Sharealike 2.5.

Hotter?

Colder?

One of these things is not like the others

Other things effect tree growth other than temperature

Drought, shade from other trees blocking sunlight, etc.

There's a maximum amount a tree can grow no matter how warm it is.

Image credit: Wikimedia user 1-1111.Licensed under GNU Free Documentation 1.2Image credit: Stefan WernliLicensed under Creative Commons ShareAlike 2.5Image credit: Wikimedia user Crusier.Licensed under GNU Free Documentation 1.2Image credit: Wikimedia user Salix × sepulcralis.Licensed under GNU Free Documentation 1.2Image credit: Harald KösterLicensed under Creative Commons ShareAlike 2.5

Sometimes when you try to turn a

Into a you get a

Reason #2 to be (scientificaly) skeptical about AGW

Any time you see a long-term climate record chart (like the one I used earlier), you should ask yourself: "How many different data types did

they use, and how accurately were the data sets spliced together?"

It's easy to mess this up.

An Inconvenient Truth?

The history I've shown so far iswhat was the consensus view upuntil the 1990s.

Michael Mann challenged this in a paper in the journal Nature in 1998*,which said:

Climate has been much more stable than previously thought

The climate started warming dramatically around 1900

The warming is likely due to significant amounts of the greenhouse gas Carbon Dioxide being released into the atmosphere

Al Gore made this ”Hockey Stick” shaped graph famous, and used in the UN's IPCC report of 2001.

* Mann, Bradley, Hughes; "Global-scale temperature patterns and climate forcing over the past six centuries”; Nature, 1998, pp. 779-787.

Hat trick or icing?

Red data is from thermometer record, blue is from proxiesSource: 2001 UN IPCC, Third Assessment Report

You don't hear much about Mann's 1998 Hockey Stick anymore

That's because it's wrong

Two amateur researchers – Steve McIntyre and Ross McKitrick – demonstrated that the Hockey Stick was fatally flawed:

One of the data sets was inappropriate for use as a temperature proxy, but was used anyway.

Mann's computer program that calculated global temperature produced a hockey stick shaped output even when random data (e.g. Stock prices) was used as input.

There is reason to believe that Mann knew that he was using inappropriate data, and used it anyway.

See ”Caspar and the Jesus Paper” for an introduction to Mann 1998, linked from:http://borepatch.blogspot.com/2009/12/should-you-be-global-warming-skeptic.html

Image credit: Wall Street Journal

Reason #3 to be (scientificaly) skeptical about AGW

The ”Hockey Stick” is a big problem for AGW proponents. Mann's 1998 article that was used

to justify the UN IPCC report is no good.

AGW proponents have been scrambling for several years to find a replacement Hockey

Stick that holds up. So far, they haven't.

But let's take a closer look at the Hockey Stick

Red data is from thermometer record, blue is from proxiesSource: 2001 UN IPCC meeting, Third Assessment Report

See the splice?

Remember Reason #2?

Be careful when yousee spliced data.

They're joining Apples to Oranges – are theydoing a good job?

Well, we see a bigchange in the shape ofthe curve, right at thesplice. That's a good reason to be wary.

This graph is hard to read, because all the data has been munged together. Let's look at a more recent graph from the IPCC which shows the different data sets independently.

The Splice

The Very Model of a Modern Major Hockey Stick

Source: IPCC, Fourth Assessment Report

You are

here

Medieval Warm Period Little Ice Age

What if you don't splice?What if you only used proxy data?

Medieval Warm Period Little Ice Age

What happened to my hockey

stick?

We removed the Thermometer Data.This is all data from tree rings. You're comparing Apples to Apples.

Reason #4 to be (scientificaly) skeptical about AGW

Any time you see a sudden and dramatic change at exactly the place that two different data sets were spliced together, you should wonder if the

change is due to the splice.

But the thermometers show warming, don't they?

Well, that's what we're told.

But you need to understand that there are two parts to the data:

Raw data. This is the numbershowed on the thermometer.

Adjustments. Sometimes the raw data is ”corrected”. Image credit: Wikimedia user 1-1111.

Licensed under GNU Free Documentation 1.2

What's with adjustments, anyway?

Data gets adjusted for a number of reasons:

If the hottest part of the day is 2:30 PM, and you read the thermometer at 10:00 AM, then your raw data will probably read low.

If you move a weather station to a new location, the new site may be hotter or cooler than the old one.

You don't want sudden jumps in the temperature record due to is sort of ”operator error”.

However, it looks like more than half of all raw data is adjusted.

Image credit: Wikimedia user Dori.Public Domain image.

How much of the temperature increase is due to adjustments?

A lot. Probably most. Maybe all.

Adjustments are so extreme that it is possible that the earth is cooling, but temperature increases are reported.

This is where the action is with the Global Warming controversy. Many people are looking at the raw data from weather stations all over the world.

They're finding a lot that's really interesting.

Darwin, Australia

0.7ºC cooling in raw data turned into 1.2ºC warming during 20th Century

Rawdata

Amount of adjustment

Adjusteddata

Source: http://wattsupwiththat.com/2009/12/08/the-smoking-gun-at-darwin-zero/

Brisbane, Australia

0.6ºC cooling in raw data turned into 0.6ºC warming during 20th Century

Source: http://thedogatemydata.blogspot.com/2009/12/raw-v-adjusted-ghcn-data.html

New Zealand

All reported warming since 1850 seems to be due to adjustments.

Source: http://www.climatescience.org.nz/images/PDFs/global_warming_nz2.pdf

West Point, New Yark

Old years adjusted downwards, recent years adjusted upwards

Raw Data Adjusted Data

Source: http://thevirtuousrepublic.com/2009/12/09/looking-for-global-warming-at-west-point-raw-data-versus-homogenized-data/

Continental USA (Lower 48)

The lower 48 states warmed by 0.6ºF in the 20th century.

Overall adjustments made up 0.5ºF of that.

Source: http://www.ncdc.noaa.gov/img/climate/research/ushcn/ts.ushcn_anom25_diffs_urb-raw_pg.gif

Reason #5 to be (scientificaly) skeptical about AGW

The raw temperature data has been ”adjusted”. The adjustments make up most or all of the

reported warming.

Sometimes the raw data show cooling, but adjustments create a large reported warming.

How the adjustments are done is poorly explained.

Meadows are cool, parking lots are hot

Asphalt roads and parking lots warm up in the shunshine.

On a hot summer day, which do you want to cool off?

Which would make a better location for a weather station?

Image credit: Wikimedia user BerigLicensed under Creative Commons ShareAlike 3.0 Image credit: estations.org

Urban Heat Island

When cities grow, they getmore buildings and roads.

These buildings and roads capture heat.

This added warmth is called the ”Urban Heat Island” effect.

Is what used to be a field surrounding the weather station's thermometer is now a parking lot?

Chicago at night, from the International Space StationImage credit: NASA

Let's look at a weather station This is the Marysville, CA weather station (MMTS).

100 years ago, there wasn't any parking lot. Or air conditioner exhaust.

Source: http://surfacestations.org/

How many weather stations are effected by Urban Heat Island?

90% of weather stations read more than 1ºF hot due to poor siting.

8% of stations read more than 5ºF hot due to poor siting.

69% of station's sites are ”poor” or ”very poor”.

Source: http://surfacestations.org/

Reason #6 to be (scientificaly) skeptical about AGW

Many formerly rural weather stations have now been surrounded by growing cities.

Much or all of the reported temperature increase is likely due to the city Urban Heat Island effect,

not global climate change.

The Surfacestations.org group is documenting as many of the 1200+ US weather station

locations.

The Greenhouse Carbon Dioxide (CO

2) is a Greenhouse Gas, as are methane

and water vapor.

A greenhouse gas lets the sun's light pass through to the earth, where it is absorbed and re-emitted as heat. The greenhouse gas blocks the outgoing heat, raising the temperature.

We're told that by burning fossil fuels, we're heating the planet due to the released CO

2.

Image credit: National Rural Knowledge Network, via Wikimedia. Licensed under Creative Commons 2.0

So is Carbon Dioxide a good greenhouse gas?

No.

Each additional portion of CO2 added to the atmosphere has

less of a heating effect than the last one.

As you put more and more CO2 into the atmosphere, it has less

and less effect (”Negative Feedback”).

But all you hear about is Carbon Dioxide. Why?

Proponents of AGW have advanced a theory of ”Positive Feedback”, where the warming power of CO

2 is multiplied, or

”forced”.

Sort of like Popeye with a can of spinach.

The problem is that the Universe almostnever works that way.

Negative Feedback keeps the Universestable, and from running away out of control.

Image credit: Wikimedia. Public Domain image.

Name three positive feedback systems in nature. Get back to me on that when you're done.

- Blogger ep

http://www.finemrespice.com/node/71

A blogger? That's not much of a response to the AGW proponents.

Positive CO2 Forcing climate computer models predict a ”hot

spot” in the atmosphere in the tropics, in the middle Troposphere.

We do not see it. Lots of people have looked.

1910 – 1940: temperatures rose, CO2 didn't.

1940 – 1975: temperatures fell, CO2 rose.

1975 – 1998: temperatures rose, CO2 rose.

1998 – 2009: temperatures fell, CO2 rose.

75% of the last 100 years does not support ”more CO2

causes higher temperature.”

The temperature record doesn't support it, either:

Reason #7 to be (scientificaly) skeptical about AGW

AGW needs postive forcing of CO2 to work.

We don't see it.

Quite frankly, this isn't surprising – you don't see positive forcing just about anywhere in the

Universe.

But what about the ”consensus” that the ”science is settled”?

Actually, there's never been a consensus among scientists.

But it doesn't really matter, anyway: Science simply doesn't care about a consensus. Your result is reproduceable, or

it's not. If everyone can reproduce your

result, it's good science; if not, then it doesn't matter who says ”it's all settled.”

If you've come this far, you know that it's not settled.

Image credit: Wikimedia user Rex Szeto. Public Domain image.

The most important thing you need to know

Image credit: Wikimedia. Public Domain Image

More than anything, science relies on data.

The most elegant theory is meaningless if the data do not support it.

Quite frankly, the data give us plenty of reasons to be skeptical.

But what else could it be?

Dunno.

The Sun?

Natural variation?

Elves?

AGW skeptics really don't have to propose alternatives.

It's up to AGW proponents to show that their theory holds water.

Image credit: Robert A. Rohde, via Wikimedia. Licensed under the GNU Free Documentation 1.2

In Summary:

It's been warm – and cool – in the past. It's been warming up for 300 years. It's not clear how burning fossil fuels since 1850 explains this.

When you see long-term climate reconstructions, ask how many data sets were used and how they were spliced together.

The ”Hockey Stick” graph has been shown to be wrong. AGW proponents haven't found a replacement that holds up.

The raw temperature data has been adjusted aggressively. It looks like it's changed the results. Nobody has explained why.

Many weather stations that used to be rural are now in the middle of rapidly growing cities. This makes them read high.

”Positive Forcing” hasn't been shown to fit nature, for CO2

or for pretty much anything else.

Where to go for more information

My web site has this presentation, as well as an article covering the same material.

I link to the sources in the article, so you can check my data.

After all, you should be ask skeptical of me as of anyone else. Click here