Tag Archives: severe weater

photo credit: onlysimchas.com

Global Warming: Questions and Answers

Don’t the record snowstorms hitting the Northeast mean there is no such thing as global warming?

No, not at all. No one single event event, cold or hot, wet or dry, can be blamed on global warming or used to deny global warming. Global warming is due to increased amounts of heat trapping gasses in the atmosphere. A Higher average global temperature is just one outcome. Snowstorms are dependent on atmospheric moisture and warmer air holds more moisture. As long as the temperature at the base of the cloud is below freezing, it will snow. The higher the (below freezing)temperature, the greater the snowfall.

More rainfall will be better for crops then, right?

Not necessarily. Not only is a warmer atmosphere wetter, it is also more dynamic. Severe storms will be more common, including flooding. Even without floods, too much rain can be a problem. Too much rain in the spring can delay planting. Too much rain in the fall can cause problems with harvesting. Both effects will lower crop yields.

cropflood

cropflood

Well then at least we don’t need to worry droughts, right?

Not necessarily. Global warming is the cause, climate change is the effect. Climate scientists make predictions for the future climate based on computer algorithms called Global Climate Models (GCMs). There are several of them and they all generally agree. Not only will the atmosphere get warmer but other changes will occur. Rainfall will be greater overall, but the distribution patterns will change. Precipitation in coastal areas will increase but in mid-continental areas it may increase only slightly or actually decrease.

drought

drought

Wait, you can’t have it both ways can you?

Actually yes. Consider the following scenario. Here in Arkansas the climate is predicted to shift from one amenable to mixed hardwoods such as an oak/hickory biome to a more savanna like climate. Rainfall may increase but it will come in fewer, more intense storms. The factor that is most important to plant growth is soil moisture during the growing season. Higher temperatures mean faster evapotranpiration. The Ozarks very well may become a badly eroded prairie-like biome. We are predicted to have more rain but a drier climate.

Even drinking water may become harder to get – or at least more expensive. Fewer but more intense rainfall events means more runoff. This means less recharge of natural aquifers so less well water. Reservoirs will need to be greatly expanded to capture larger rainfall events.

Well, at least it won’t cost so much to heat homes and offices in the winter, right?

OK, I’ll give you this one but over all utility bills may be higher due to the greatly increased demand for air conditioning in warmer months. Summer electric loads are currently higher in the summer than winter, and this differential will expand. Not only will hotter summers cost more, heat waves will become more frequent. Heat waves are already the most lethal extreme weather event.

The climate has changed in the past and we survived. Why is this any different? Climate has changed before but never as rapidly as it is/will be changing in the near future. We will no doubt survive but a lot of plant and animal life won’t. Our future will be hotter, both drier and wetter, more lethal, and less diverse unless we act and act fast.

Colorado River

Extended Drought in Southwestern US

One of the projections of climate change due to global warming is alterations in rainfall patterns. Warmer air will hold more moisture so one might think that global warming will cause more rainfall and generally that is true overall, but another feature of global warming is a redistribution of rainfall, more falling on the coasts and less in the continental interior.

Additionally, the rainfall patterns are predicted to change to more intense storms where larger amounts of rain occur over shorter time spans. Heavy rains mean more runoff, hence less water available for the myriad of uses we depend on – energy production, agriculture, industry, recreation and most importantly drinking water.

>The Colorado River and its tributaries drain a basin of a quarter million square miles. Forty million people in six western states [Colorado, New Mexico, Utah, Wyoming, Nevada, Arizona] are directly in the line of fire of climate change. For millions of years the Colorado has flowed from the upper reaches of the Rockies to a large delta at its confluence with the Gulf of California.

Not so much any more. A combination of drought and pressure on the river from agriculture and burgeoning cities has reduced the flow to the point that in recent years the Colorado no longer reaches the sea. Virtually every drop is removed for irrigation in the Imperial Valley of California, to cool coal-fired power plants around the Four Corners area, and to water golf courses in Phoenix.

Global warming and the attendant climate change is predicted to decrease precipitation by twenty percent in the watershed over the next forty years. This will greatly exacerbate the issue of the availability of water in the southwest. The water level of Lake Powell,

Lake Powell on Colorado River

Lake Powell on Colorado River

formed by the construction of the Hoover Dam is at an all time low, some 120 feet below its high of a decade ago. Images show what appears to be a “bathtub ring” on sandstone bluffs along the lakeside.

Another distressed southwestern watershed is the almost two thousand mile long Rio Grande which demarks much of the border between the US and Mexico. The two hundred thousand square mile basin has been stressed by a decade long drought, and it appears to be getting worse due to global warming. Two significant reservoirs, Elephant Butte and Caballo are at less than ten per cent capacity.

Elephant butte Reservoir

Elephant butte Reservoir

Like the Colorado, the Rio Grande doesn’t make it to the sea. What little flow exists is removed, mainly for irrigation. The flow essentially ends by the time it reaches Presidio, TX.  Other significant water courses in China, India and Australia are distressed to the point of no exit flows. The problems are real and worsening with increasing population demand and climate change.

Global warming is real, we are causing it and we need to address how to stop,even reversed it, in addition to the immediate need for adaptation to the new climate we are forcing.

Severe Weather and Global Warming

Yet again Moore, Oklahoma has been hit with a monstrous tornado. In 1999 Moore suffered a EF-5 tornado, the most intense in the rating system. The 2013 storm followed essentially the same path, and is quite likely to be another record breaker in terms of intensity and damage.

It’s no coincidence that the National Weather Service Storm Prediction Center is in Norman, OK as this region is known as tornado alley. The area is where collisions of cold fronts from the plains are most likely to collide with warm moist air from the Gulf, the conditions which generate storms and tornadoes. Generally the warmer and more moist the air, the stronger the tornado.May_20,_2013_Moore,_Oklahoma_tornado

So the big question is why this storm now? Is it just a random occurrence or is there a connection with global warming? There is no question that global warming is occurring and is driven by human activities such as burning fossil fuels and worldwide deforestation. 2012 was the hottest year in recorded history in the United States. Last year’s drought in the midwest was the most severe since the 1950’s. Globally, eleven of the hottest years on record since 1880 have occurred in the last twelve years.

The United Nation’s weather agency has confirmed that 2012 was the 27th consecutive year that global land and ocean temperatures were above average. Last year exceeded the global average temperature of 58 degrees Fahrenheit despite the cooling influence of a La Nina weather pattern, according to the World Meteorological Organization’s annual climate report.

As human activities continue to flood the atmosphere with heat trapping gases, the temperature of the atmosphere rises. A warmer atmosphere over time means climate change. Attendant with climate change are variations in weather patterns. Warmer air is wetter air. Precipitation events can become more intense, meaning flooding is more likely. Severe storms which spawn tornadoes are the result of warm moist air colliding with cooler air- the warmer and more moist the air, the more severe the storms. Paradoxically droughts in mid-continental regions are predicted due to changes in weather patterns. Examples abound.

At the expense of repeating myself, no one weather event can be blamed on global warming, but the pattern of events we are seeing are consistent with what one would expect as a result of global warming and climate change.

Are EF-5 tornadoes to be the new normal? Only time will tell, but if these conditions persist in future years not only will the environment be impacted but also the economy. And that is dangerous.

Denial of the risk of global warming persists but is waning. Something like sixty per cent of Americans now believe global warming is happening, and is due to human activities. The denial is somewhat understandable because to accept the reality of global warming is to accept culpability. We individually and collectively don’t want to recognize that when it comes to global warming we are the major actor. Each and every one of us is to blame to some degree.