Global Warming METR 205

The Problem as Environmentalists see it Rising Global Temperatures artificially induced by fossil fuel burning, tree cutting, etc. Severe consequences of rising temperatures  Sea level rise  Crop failures  Severe heat waves  Extinctions  Shifts in weather patterns (storms)

But are temperatures really rising? Since 1880, it would appear to be so. From

Many scientists have published graphs showing increasing temperatures. This one is from the University of East Anglia in England. (

The IPCC uses the same data as the Univ. of East Anglia. Here’s the graph in the 2013 report:

Temperatures are higher now than at any time in the last two millenia The current rise in temperature correlates quite closely with the rise in Carbon Dioxide.

The last time the global temperatures were high (~1000 A.D., the Vikings settled Greenland and discovered Vinland (North America)

How do we know what the global temperature will do in the next 100 years? General Circulation Models (GCMs)

Some of the GCM predictions are startling.

Some of the changes seem to be happening.

From

In March 2002, the Larsen B ice shelf broke off from Antarctica and melted. The area in the pictures is 93 x 116 miles! Picture from /IOTD/view.php?id=2351

Nov 2, 2011: Huge Crack Discovered in Antarctic Glacier ( Apparently, the melting is still occurring.

Computer models suggest that global warming could intensify hurricanes (does Superstorm Sandy prove this is really happening?)

From

Some worry that changing the global air temperature will impact the oceans’ circulation, possibly having a drastic feedback effect on the atmosphere.

So, the environmentalist view is this: And they are telling you about it now, so do something! Is this all true? It seems so obviously correct.

The Skeptics’ View of Global Warming Global mean temperatures are notoriously difficult to measure, especially before Temperatures are strongly biased by their locations in mid-latitudes, industrialized societies, in urban areas. The computer models that predict global warming are incomplete, flawed, and unable to make such forecasts. Very little direct evidence for global warming exists in the 25 years that scientists have been following it.  Sea level is not rising  Storms are not increasing in strength or numbers  Coast lines have not been inundated

The Skeptics’ View of Global Warming (continued) Environmentalists have a vested interest in sounding the global warming alarm. They benefit from it. Correlation is not causality. Just because temperatures appear to be rising at same time as CO2 doesn’t prove the Greenhouse effect is causing the world to warm. Fixing this “problem” will cause tremendous hardships for ordinary people, governments, and businesses.  Big costs involved in building levees in low-lying areas  Jobs lost as productivity goes into reducing emissions  Switching from fossil fuels will cost people plenty for powering vehicles and heating homes.

First of all, are worldwide temperatures really increasing? It depends on who you ask. From

Here’s that NASA graph again. The increase in temperature has actually stopped or paused for about 10 years.

A close-up look at the Pause. From ray-2013-coverage-bias-in-the-hadcrut4-temperature-series-and-its-impact-on-recent-temperature-trends/

Global warming proponents push Carbon Dioxide as causing the warming but the rise in CO 2 is very steady while the change in temperature is not. Clearly there are other factors operating. You can’t ignore big processes like El Niño.

Does CO 2 cause global warming? Look carefully. Sometimes temperature change precedes the CO 2 rise. From Temperature change (blue) and carbon dioxide change (red) observed in ice core records.

Is sea level rising? Not since 1841 says John Daly

So, if humans aren’t responsible for global warming, what is? How about sunspots? If the sun is changing, the basic heating of the Earth is changing, too.

CO2 is actually a very small contributor to the GH effect. Water vapor is the biggest culprit and people contribute very little to the amount of water vapor in the atmosphere.

The Urban Heat Island can account for most of the reported “Global Warming”

Meteorological stations in Eastern Ontario and Southern Quebec, Canada Urban heat island effect on temperature trends in Eastern Ontario, Canada by Andreas Prokoph of Speedstat Consulting & Carleton University, Ottawa, Canada

Temperature Records

But what about the hurricanes? The following figure, from a recent study published in Science, shows that, since 1970, Cat hurricanes have become more numerous:

The authors used data from 1970 on so as to have a homogenous data set of storms discovered using satellites only. But Category 4-5 storms are probably always detected. Using data from aircraft since 1945 shows the violent Cat. 4-5 storms actually decreased to a minimum in 1970 and are now getting back to where they were in It’s just a natural cycle.

Named Cyclones by Year ( Bars depict number of named systems (open/yellow), hurricanes (hatched/green), and category 3 or greater (solid/red), ) ) Now found at

So, what should we do about Global Warming? Environmentalists: Fix it now before it’s too late. Skeptics: Fix other (real) problems, like terrorism and the economy, instead.