Was this blizzard or that hurricane or that drought “caused” by human-caused global warming? Michael Mann, a climatologist who directs the Earth System Science Center at Pennsylvania State University, used this basketball analogy to illustrate this causation issue:
If you take the basketball court and raise it a foot, you’re going to see more slam-dunks,” Mann said. “Not every dunk is due to raising the floor, but you’ll start seeing them happen more often then they ought to.
Often when I comment on golbal warming, I tend to get knee-jerk accusations from others calling me a global warming denialist. Because I doubt that CO2 from human activity is the major controlling factor of global warming, they assume I think human activity has no influence at all.
My suspicion is that CO2 is a co-effect rather than a causation, because tightly coupled correlation are more likely to be co-effects.
There are many macro processes that affect weather and climate. For example, differences in the evaporation of ocean water will be reflected in changes in humidity, rainfall, ocean currents, droughts, and even storm patterns. Imaging the effect of reducing the evap rate of several hundred square miles of ocean for several months with a massive oil spill.
Research also indicates that agriculture, particularly involving irrigation, produces significant levels of greenhouse gases other than CO2. Some crops, such as corn, seem to be worse for the climate, largely due to the use of chemical fertilizers such as ammonium nitrate.
Since the initial studies in Canada several years ago, the effects of irrigation have been alternately championed and refuted by research and studies favoring one side or the other of the issue.
“I doubt that CO2 from human activity is the major controlling factor…”
BUT NIK, AS FAR AS I KNOW, HUMAN ACTIVITY IS THE ONLY FACTOR THAT WE can (hopefully)* influence on a scale large enough to effect the climate. Although if we asked the pigs nicely to stop farting they would surely comply. In other words, how is your giant space umbrella plan coming along?
(Interestingly, I note you/Nik have a harder time “trusting” the SCIENTIFIC CONSENSUS of climatologists than you do other highly educated science authorities such as rocket scientists or physicians)
FYI this was not a knee-jerk reaction. Erich please remove Niklaus’s commenting privileges. 😉
* my biggest area of doubt is not whether we can affect the climate, but whether the effect that we have is positive or negative for us or even vs. animals/nature) and in what time scales (ie 50 year, 500 year, 5,000year).
Ben,
Your comment exemplifies the very meme I was describing. I simply don’t buy into the idea that a system as complex as the global climate can be completely modulated by small changes to a single, relatively insignificant parameter while other human activities are ignored that also alter the energy dynamics of our atmosphere and oceans. These are the energy dynamics controlling weather and climate.
It is pollitically expedient to push co2 as the only cause of global warming, because the industrialists intent on raping the planet can appear concerned, make a fortune in speculative trading of carbon credits while doing nothing to address the problem. If the IPCC seriously want to reduce co2 emmissions, they would not approve the trading of carbon credits. Trading carbon credits is a end run around the caps.
BTW, Ben, your farting pigs comment comes across as very asinine.
A true scientist has no faith in what people believe, only in what can be scientifically proven.
The Earth’s climate is changing rapidly. Scientists trying to find out what’s causing climate change work like detectives, gathering evidence to rule out some suspects and to ascertain just who is responsible. It’s clear, based on over a century of scientific investigation, that humans are responsible for most of the climate change we’ve seen over the last 150 years.
Humans are not the only suspects. The climate has changed throughout the Earth’s history, well before humans evolved. The Sun is the primary driver of the climate. Roughly speaking, global temperatures rise when more energy from the Sun enters the atmosphere than returns to space through the atmosphere. The climate cools any time more energy returns to space than comes in from the Sun. While humans can influence that balance, other factors, from continental drift and changes in the shape of the Earth’s orbit to variations in the Sun’s activity and phenomena like El Niño, can all influence the climate. Considering the pace of climate change today, scientists can rule out most of those suspects: some happen too slowly to explain current climate change, while others move in small cycles, not long trends, and others only influence the climate in part of the planet. Scientists know about these factors and can account for them when assessing human-caused climate change.
http://ncse.com/climate/climate-change-101/how-much-human-responsibility-for-climate-change
http://ncse.com/climate/climate-change-101/is-climate-changing-now
Carbon dioxide is rising because of human actions: Scientists can measure the increase of atmospheric carbon dioxide over the last 150 years. By comparing the type of carbon being added to the atmosphere, they see that the kind of carbon released by burning coal, gasoline, and natural gas is diluting the naturally-occurring carbon dioxide in the atmosphere. Data from Trudinger, et al (1999).
For over 100 years, scientists have regarded humans as the prime suspect in current climate changes. Around the turn of the 20th century, Svante Arrhenius was the first to suggest that people could, through the burning of coal, increase the amount of greenhouse gases in the atmosphere and amplify the natural warming effect, thereby causing the atmosphere to warm more than it would through strictly natural processes.
When humans burn gasoline, coal, natural gas, and other common fuels to make electricity or drive cars, they release a substantial amount of carbon dioxide into the atmosphere. For every gallon (or liter) of gasoline your car burns, 1300 times that volume of CO2 is released (a gallon of gas weighs about 6 pounds or 2.8 kilograms, but the released CO2 would weigh over 19 pounds or 8.75 kilograms). Greenhouse gases are emitted from power plants and cars, but also from landfills, from farms and cleared forests, and through other subtle processes. An interactive map from the Environmental Protection Agency shows US sources of key greenhouse gases. The World Resources Institute cataloged (PDF) global sources of greenhouse gases in 2005.
In the 1950s, scientists began methodically measuring global increases in carbon dioxide. Since then they’ve been able to confirm that the increase has been caused primarily from the burning of fossil fuels (and through other human activities, such as clearing land, as well). This increase, and changes in the type of CO2 being added to the atmosphere provide the “smoking gun” that shows that humans are responsible for the increased levels of carbon dioxide in the atmosphere.
To clinch the case that climate change is mostly caused by humans, scientists had to take into account other factors: complicated atmospheric physics, the interactions between air and land and between air and water, changing amounts of ice and of desert and forest, and the natural processes that have changed the climate for 4.54 billion years. To do all this, scientists recreate the crime scene. Because there’s only one Earth, they do that with computers. Climate scientists use powerful computers to construct models based on physics of the climate system. These models enable scientists to make predictions and test hypotheses about what processes affect the climate.
I simply don’t buy into the idea that a system as complex as the *human body* can be completely modulated by small, relatively insignificant *germs* while other human activities such as poor diet and lack of exercise are ignored — that also affect our overall health.
It is politically expedient to push germs as the only cause of sickness, because the pharmaceutical companies — intent only on profits, make a fortune in speculative trading of designer medicines. Meanwhile the real problem — Americans’ sugary, fatty diet and sedentary lifestyle is largely ignored.
Ben,
You’re spreading it pretty thick. First and foremost, I have not denied global warming, nor have I denied that human activity is impacting the climate. In fact, my opinion is that replace all fossil fuel use with renewable energy, we will continue to screw with the climate.
Yes I know that a “Consensus of scientists” believe that co2 is causing global warming. Most laymen assume the scientists in the consensus are all climatologists. Not true. It takes a bit of digging, but you can find the names and credentials of the original consensus, and surprisingly, most of them were not climatologists.
Ben, your germ analogy, possibly intended as a mockery is actually pretty accurate as an assessment of industrialized medicine. But even in that case a single species of germ is not responsible for every conceivable illness.
Additionally, proper nutrition and excercise strengthens the body’s fight off infection and conversly inproper nutrition that toxifies the body greatly adds to the likelyhood if dangerous infection. Take the word of a diabetic who nearly died from Fournier’s Gangrene a few years ago.
BTW, the computer models are constantly being adjusted in attempts to match the modelled forecasts to real world data.