A week before I began writing this column, my wife and I discussed what we thought was a peculiar but deliberate policy of The New York Times front-page editors, namely, they never discussed or even mentioned global warming or climate change on the front page! We have believed for a long time that global warming from our emissions of CO2 into the atmosphere is the story of the century. So we decided that we needed to picket their NYC building and get publicity for what we believe is a terrible policy for our country and an extremely bad policy for the "paper of record."

We "talked the talk" but did not "walk the walk." However, on Sunday, 15 August 2010, the Times printed a front-page story, headlined: "In Weather Chaos, a Case for Global Warming." An important part of that front-page story is fact that the entire world is confronted with a difficult problem: how to tell when and if global warming is determining our weather. Are the recent extreme and terrible floods such as the one now ruining Pakistan a manifestation of global warming? Are the recent extreme heat waves and record temperatures in Russia a manifestation of global warming?

These questions are at the heart of many significant discussions and controversies about global warming. Determining that global warming from CO2 buildup in the atmosphere is actually occurring now and growing worse would be a vitally important event for mankind; it would mean that everyone would have to start immediately reducing emissions of greenhouse gases.

A new field in climate science has developed over the last 40 years, namely computer modeling of the earth’s climate from first scientific principles. It is these climate models that we must rely on for predictive purposes. Climate scientists from all over the world have developed complex, thermodynamic climate models for the earth that determine the future global climate given various annual emissions of CO2 into the atmosphere. When these models have been run using CO2 emission data, El Nino and La Nina information, solar radiation incidence, as well as volcanic eruption data from the past as starting points, they correctly predict the annual average global temperatures and trends that have actually been observed right up to the present time.

"Predicting" the past gives confidence in our ability to predict the future; yet these climate models’ future predictions are dire indeed. Much higher average temperatures, heat waves, floods, and rising ocean levels are the predictions if the world continues to burn fossil fuels. "Hell and High Water" is the expressive main title of Joseph Romm’s must-read book (Hell and High Water: Global Warming--the Solution and the Politics--and What We Should Do, by Joseph Romm, Harper Collins, 2007).

Let me begin to answer the questions I posed in the second paragraph by asking and answering an easy question. What is what is meant by the words "climate" and "weather"? A dictionary definition of climate: "The meteorological conditions, including temperature, precipitation, and wind, that characteristically prevail in a particular region." A dictionary definition of weather: "The state of the atmosphere at a given time and place, described by specification of variables such as temperature, moisture, wind velocity, and pressure."

In contrast to weather, climate is a collection of regional weather patterns over a long-time. As examples, a "dry, hot climate" such as that of our South West is characterized by few days of rain, a generally low humidity, and temperatures in the 90’s and 100’s during typical sunny summer days. New England is characterized by four distinctly different seasons, with rainfall each month of about 10 inches of rain in spring, summer, and fall, and with considerable snow in the winter. Additionally, weather in New England is quite changeable; no pattern is discernable and no one weather type continues for many consecutive days.

Our climate models predict a slowly increasing average annual temperature throughout the planet, an increasing amount of rainfall in areas that now already have a lot of rainfall, and those areas that are dry now will become increasingly drier because increased temperature will accelerate the evaporation of whatever soil moisture exists. These trends will be on top of the normal weather fluctuations we have experienced all our lives. In fact, the annual average land-temperature fluctuations (about 0.2 ºF per year) are considerably larger than the measured average annual increase of global land temperatures (about 0.03º F per year) for the last three decades. This measured average increase agrees with the predictions of global warming climate models. Because the annual fluctuations are larger than the annual average increase, it cannot be said with confidence that an increase in global annual average temperature for any particular year is due to global warming, however.

The U.S. National Oceanic and Atmospheric Administration (NOAA) recently issued a key report, "The 2009 State of the Climate Report." This new report draws on the work of 303 scientists from 48 countries, and includes data from last year. NOAA’s report identified 10 key planet-wide indicators of a warming climate:

1. Higher temperatures over land

2. Higher temperatures over oceans

3. Higher ocean heat content

4. Higher near-surface air temperatures (temperatures in the troposphere, where Earth’s weather occurs)

5. Higher humidity

6. Higher sea surface temperatures

7. Higher sea levels

8. Less sea ice

9. Less snow cover

10. Shrinking glaciers

The seven indicators expected to rise in a warming world did rise over the last decade, and the three indicators expected to decline, #8, #9, and #10, did so over that same period. As these ten indicators become more and more obvious to the world at large and not just to scientists then the world will take action to stop CO2 emissions. Let us hope it will not be too late, because already the warming and its consequences are serious.

The decadal average global temperature has been increasing for the last five decades. This fact should cause us to pause and consider that global warming is occurring with a high probability. How many decades of warming will it take before everyone agrees and takes action?

It is not just the rise of average temperatures that is an indicator of global warming; weather extremes are other potent indicators. The first half of 2010 shattered many high temperature records since the inception of continuous thermometric record keeping in 1879. It is not just Russia that is sweltering this summer. Belarus, Ukraine, Cyprus, Finland, Qatar, Sudan, Saudi Arabia, Niger, Chad, Kuwait, Iraq, Pakistan, Colombia, Myanmar, Ascension Island, and the Solomon Islands all broke or tied their all-time national temperature highs this year, according to an analysis by meteorologist Jeff Masters of Weather Underground. Globally, including the ocean surface, the first half of 2010 has been the hottest in thermometric recorded history.

Pakistan also achieved the dubious distinction of "the hottest reliably measured temperature ever recorded on the continent of Asia," Mr. Masters wrote. That record was broken by the unfortunate city of Mohenjo-Daro in south-central Pakistan, which reached a stunning 128 degrees Fahrenheit on May 26, 2010, according to the Pakistan Meteorological Department.

Perhaps the best way to see how temperatures have been going up in the U.S. (The world has been about the same as U.S.) is to examine, year-by-year, the number of new record highs versus the number of new record lows at the thousands of weather stations in the contiguous 48 States. The ratio of new highs to new lows has gone up every decade since the 1960’s; the ratio reached 2.04 in the 2000’s. In other words, there were more than twice as many new high temperatures set during the last decade than new lows. In a decade without global warming, one would expect a ratio of 1. Ratios were below 1.0 in the 60’s and 70’s partly due to volcanic eruptions (Agung in 1961) whose fine particle emissions reached high into the atmosphere where they reflected in-coming solar radiation back into space thereby cooling the earth. Mt. Pinatubo’s eruption in 1992 also cooled the climate for a couple of years in the 90’s in the U.S.

Of great concern is the amazing speed that Arctic sea ice is melting, 34,000 square miles each day this June. That was more than 50 percent greater than the average rate of 20,000 square miles a day set in 2006. Average June ice extent in the Arctic was the lowest in the 31-year satellite data record. Loss of ice and snow cover reduces earth’s albedo, further increasing the earth’s temperature in a dangerous feedback loop we must avoid.

There are other weather signs of global warming to consider beside extreme temperature records. Climate models predict extreme flooding and rainfall records because global warming increases the evaporation of water from the oceans. Every 1-degree Centigrade increase causes a 4% increase in air humidity and climate scientists believe that for every 1-degree Centigrade increase in average temperature there will be a 3-10% increase in heavy rainfall. The area burned by wildfire in parts of western North America is expected to increase by 2 to 4 times for each degree of global warming. There will be 5–15% yield reductions of a number of crops for each degree of global warming.

Devastating flooding that has swamped one-fifth of Pakistan and left millions homeless, 20 million displaced, and about 1600 dead is likely the worst natural disaster so far attributable to climate change, U.N. officials and climatologists are now openly saying. Most scientists have cautioned in the past against tying any specific event directly to emissions of greenhouse gases. But scientists at the World Meteorological Organization (WMO) in Geneva say there is no doubt that higher Atlantic Ocean temperatures contributed to the Pakistan disaster begun late last month.

Special Envoy to Afghanistan, Richard Holbrooke, announced on the PBS News Hour on 19 August 2010 that this flood is probably a manifestation of global warming. This is the first time I have heard such a public admission from an important American official.

Atmospheric anomalies that led to the floods are directly related to the same weather phenomena that caused the record heat wave in Russia and flooding and mudslides in western China, said Ghassem Asrar, director of the World Climate Research Programme and World Meteorological Organization (WMO). And if the forecasts by the Intergovernmental Panel on Climate Change (IPCC) are correct, then Pakistan’s misery is just a sign of more to come, said Asrar.

During the most intense storms in Pakistan, about a foot of rain fell over a 36-hour period. Parts of the affected areas, in particular Khyber-Pakhtunkhwa province (formerly Northwest Frontier province) received 180% of the precipitation expected in a normal monsoon cycle. Records show that the famed Indus River is at its highest water level ever recorded in the 110 years since regular record keeping began.

China is witnessing its worst floods in decades, WMO says, particularly in the northwest province of Gansu. Floods and landslides have recently killed at least 1,100 people there and left more than 600 missing, feared swept away, or buried beneath mud and debris. The U.N. network of scientists reported in 2007 that rains had increased in northwest China by up to 33% since 1961, and floods nationwide had increased sevenfold since the 1950s.

Prior to this year, the hottest temperature in Moscow’s history was 37.2°C (99°F), set in August 1920. The Moscow Observatory has now matched or exceeded this 1920 all-time record five times within an eleven-day span this summer. Soil moisture in some portions of European Russia has dropped to levels one would expect only once every 500 years. The impact of the decline in soil moisture, along with the epic heat and fires, has been devastating, causing Russia to ban wheat exports. Coupled with other extreme weather around the globe, wheat prices have nearly doubled since June.

Each climate indicator is changing as expected if the world were warming due to increasing CO2 in the atmosphere; not a single scientific analysis disagrees with that. The bottom line conclusion that the world has been warming is simply undeniable. What is clear to me is that the United States will be making a monumental mistake if it waits for scientific certainty with respect to climate change before developing a coherent response. I judge the probability to be too great (95-100%) that global warming will greatly damage our planet during this century and beyond unless we take strong action now to stop it.

We were forewarned for months that the U.S. Senate was not inclined to go along with the House bill on Global Warming, the Waxman-Markey bill. In particular, opposition to a tax or cap on carbon emissions was bitterly fought by coal-state Democrats and most al....
Continue