A rec-listed diary connects our most recent tornado outbreak to climate change and implies its severity must be related to climate change, because a warmer Gulf of Mexico means more water vapor, or something. This diary fails to recognize that climate is a long-term measurement of atmpospheric conditions and behavior. A single severe tornado outbreak does not climate change make, nor can we measure climate change from one such single event. That doesn't mean it's not horrifying, and that doesn't mean climate change is not occurring -- but if we are going to beat science deniers on the merits of science, we have to be right on the science.
Climate is measured in decades and centuries. To declare it changed requires an accumulation of a lengthy data record. This is something that climate scientists have done through meticulous data collection during recent decades as well as research into sediment and ice cores in lakes, oceans, glaciers, and ice caps. These lengthy data records help us understand what is happening in the LONG term - again, decades, centuries - and it very strongly suggests major climate change.
For the data gathered from this single tornado outbreak to be useful, it must be considered in a context of tornado statistics from a much longer period than just last week. If such severe outbreaks suddenly became commonplace across years and decades, THAT would be a serious climate change flag. If they suddenly began regularly occurring in places where we hadn't seem them before -- if, for example, over the past ten to fifteen years we began seeing an uptick in reported tornadoes in Anchorage, Alaska, where such weather is rare -- THAT would be a major climate change flag.
We have had an exceptionally active spring in terms of tornadoes. With 871 preliminary tornado reports for the month of April alone, it's clear a record may be set once meteorologists survey the damage and report the data. According to the NOAA National Weather Service Storm Prediction Center (SPC), this far outstrips numbers from previous years, which are in the 100-200 range (3 year average is 185 tornadoes in April). If the average starts to rise because year after year we're seeing more tornadoes, that begins to raise a question about climate change, because year after year, decade on decade, what the averages helped us come to expect the weather to be no longer occurs. THIS would be data to watch for climate change.
We are seeing warmer temperatures earlier in spring further north - and that has been noted now as a continuous process across decades as flowering times of certain plants and emergences of hibernating creatures and breakups of ice along rivers occur earlier and earlier. THAT is climate change in action. But a single warm March? That's a weather anomaly.
Sometimes, the record is thin. Some phenomena are better or more frequently observed or reported than they once were because we are a more densely populated nation with better communication systems and better instrumentation for observing these phenomena than what once was the case. For example, we only began observing hurricanes by satellite in 1966. Before we had that remote sensing instrumentation, we often missed many storms which formed over, and stayed over, open ocean. Tropical Storm Zeta, for example, would likely never have been discovered and named without the satellites we have in orbit today. The freak hurricane which struck Brazil in spring, 2004 might never have been realized to be the phenomenon it was. So with a thin record, we have to try to gather more evidence before making a claim. For example, many would have leapt to claim Hurricane Katrina or the exceptionally active hurricane season of that year as evidence of climate change. And many did. However, those are short-term occurrences. One hurricane is weather. One hurricane season is a weather phenomenon. So researchers must dig up - literally - a greater data stream in order to first learn the climatology of hurricanes from the past, and then see has changed over the longer course of time. That is a study called paleometeorology. Paleometeorologists are the dedicated men and women who take sediment cores and ice cores and study the composition of trapped gases and sediments to let the atmosphere's past speak to us.
If we are to discuss climate change in a way that truly covers the issue appropriately - without being sensationalist, and without jumping to conclusions before we have data to prove them - we must discuss climate change in terms of CLIMATE. We have to get the science right. Again, it is a longer-term measure than last week, or last month, or last fall. This tornado outbreak cannot prove or disprove climate change. It is a horrific disaster, and vivid example of extreme weather - not extreme climate.
What we CAN do with this outbreak is use it as evidence for two things.
1. Government agencies can be critically necessary to save lives and protect property. This is incontrovertible evidence that a government agency used taxpayer dollars to the BEST of the public's interest. That needs to be trumpeted loudly. Government did good for the people.
2. Following on, agencies like this need to be funded fully to have the instruments and staff to properly respond to disasters of such magnitude. In the wake of such a disaster, what legislator could stand up and say that the National Weather Service is a bloated and unnecessary agency full of useless bureaucrats? None. And if he did, voters would ridicule her or him all the way to the ballot box. A recent diary noted that the Ryan budget cuts funding to NOAA and to the National Weather Service -- just when these critical events are happening.
Such WEATHER events can be useful in marketing good government and securing funding to make sure that agencies which are critical to protecting the pubic continue to be fully funded to do their lifesaving work. In the process, funding can also be secured to continue to study the longer-term change in our CLIMATE, because we can point out that the more we understand about CLIMATE, the better we are able to forecast and prepare for WEATHER events like this catastrophic tornado outbreak.
Let's discuss the issue conversantly. Let's talk about weather when we have short-term weather events, and climate when we have longer-term data at hand. And let's use both sets of data to press our elected representatives to properly fund research and response to both.Updated by ElsieElsie at Sun May 01, 2011 at 11:03 PM CDT
To respond to commenters below, I am fully on board with the clarity that human activities are causing climate change. It's not debatable, to my view.
Commenter Deward Hastings, below, said so much better and more succinctly what I mean to say:
"We rightly laugh when climate change sceptics point to a snowdrift and say 'what global warming' . . . it is . . . unfortunate . . . when some people here turn around and do exactly the same thing (in reverse) with a tornado. Being right does not excuse one from properly making the case and properly presenting the argument."