"It is clear that climate change is happening now. The observed climate changes we report are not opinions to be debated. They are facts to be dealt with."A brief overview of the science behind climate change. The greenhouse concept was discovered long ago (1824) and so accepted today that you could find the principle illustrated at any junior high science fair. When greenhouse gases are present, there is more potential to absorb heat, thus warming the surface and atmosphere of the planet. Right now, there are more greenhouse gases than ever. The concentrations of carbon dioxide and methane are higher than at any time in the last 650,000 years. Geological evidence supports that the last time there was this much CO2 in the atmosphere was 20 million years ago.
The principle that humans are contributing to global warming is well established in the scientific community. It's kind of like the principle "smoking causes cancer." Sure there will be some people even within the scientific community who claim this cannot be established as fact. They claim "other things cause cancer" or "some individual smoke and never develop cancer" but just like in global warming, these naysayers are looking at the exceptions and not at the established scientific data.
With so much data available in our world today, it should come as no surprise that there is evidence both for and against global warming. Statisticians can play with numbers and show anything they want. But in my quest to understand what is really going on, I have found more scientific literature which supports global warming hands-down. The Intergovernmental Panel on Climate Change (IPCC) is a scientific, intergovernmental organization that assesses the body of scientific literature. It bases its assessment mainly on peer reviewed and published scientific literature. The organization seeks to state only conclusive findings, rather than doomsday predictions or even highly probable, but not established theories. Because of this, what the IPCC establishes is very authoritative. While individual scientists have voiced disagreement with some findings of the IPCC, the overwhelming majority of scientists working on climate change agree with the IPCC's main conclusions. These basic conclusions have been endorsed by at least thirty scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. These conclusions are that the average temperature has increased and that most of the observed increase in globally averaged temperatures since the mid-twentieth century is very likely due to the observed increase in man-made greenhouse gas concentrations via an enhanced greenhouse effect. Three compelling points are worthy of emphasizing.
The temperature of the earth is increasing - In the last 50 years, the temperature of the earth has risen 2ยบ F. Before this, the temperature of the earth for the last couple thousand years has been relatively stable. The year 2005 was the hottest on record, based on estimates by NASA.
The glaciers are disappearing - A 2001 report by the IPCC suggests that glacier retreat, ice shelf disruption such as that of the Larsen Ice Shelf, and sea level rise are attributable in part to global warming. The consequences of this are frightening, but I will save this for another time. The key to this post is not the consequences of global warming, but that it is occurring.
The oceans are becoming acidic - Oceans are being greatly affected by climate change. Not only are the glaciers melting, as the temperatures of the oceans are increasing, the acidity of the ocean's waters are also increasing. Increased atmospheric CO2 increases the amount of CO2 dissolved in the oceans. CO2 dissolved in the ocean reacts with water to form carbonic acid, resulting in ocean acidification. Ocean surface pH is estimated to have decreased from 8.25 near the beginning of the industrial era to 8.14 by 2004, and is projected to decrease by a further 0.14 to 0.5 units by 2100 as the ocean absorbs more CO2.
Some of you reading this have the glossed look in your eyes, ready and excited to resort to your trusted global warming defenses. The first defense is other factors contribute to the temperature of the earth. The IPCC even remarks that natural phenomena such as solar variation combined with volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward. Solar flares also contribute to the earth's temperature. The argument is kind of like saying, "My lifestyle does not cause me to be fat-it's my genetic predisposition. There's no point in exercising or eating healthily doing so would not in and of itself lead me to be skinny." Just because there are other factors (which are uncontrollable by us), does not mean that we shouldn't work on the controllable factors. It is interesting to note that in 2005 (the hottest year on record) the solar flares were at their lowest levels in 30 years.
The second defense is that the earth goes in cycles. We do go in cycles, but the recent trend is not natural. Even if the hockey stick graph is not conclusive, all major models project that the earth will continue to heat up for years to come.
There are other critiques and defenses to the global warming hypothesis, and I will address them in the comment section. But why do I bring up global warming on my blog? Recognition is the first step. My motive was not necessarily to inspire a decrease in greenhouse gas consumption (although if that were to happen, I would definitely be happy. I myself try to conserve energy when I can by recycling, driving fuel-efficiently, and conserving energy. The more people that go green the better!) Mostly I wanted to first establish a fact that sadly has not been established yet. Our planet needs us to look after it better. I want to go back to Alaska and see all the glaciers that I remember seeing as a boy. My hope is for each of us to be honest when talking about climate change. Instead of saying, “There isn't enough evidence that humans are contributing to global warming,” say “I don't care about the environment” or “I care more about making money than preserving something for future generations.”
10 comments:
At the risk of sounding incredibly liberal (;P), I am often surprised that there are people that don't believe global warming is happening. How can you live in the world and think that? Sort of ridiculous....
Its kind of like me saying, "Nice data Trent. But it isn't as hot right now as it normally is this time of year, so I don't believe you."
I liked the analogy to eating habits. Well said.
well Trent You may be correct but I fear you're glossing over the real reasons many people remain dubious of man made global warming.
The infamous Hockey stick graph is rather compelling until you look closely, and discover that temperature changes are preceding the CO2 levels by as much as 800 years. If global warming is to be attributed to CO2 shouldn't it be the other way around?
another thing to note is that man made CO2 only counts for 3.5 percent of the total CO2 in the atmosphere.
Melting glaciers could be a concern though I doubt we can do much to alleviate that, however the most recent data shows that the ice sheets while melting at the extremities are now thickening in the middle.
The sun spot theory seems a fairly logical reason for the global warming. up until 2005 they had been unusually active, at which point they seem to have vanished and oddly enough the earths temp has been on a cooling trend since then. plus mars has experienced a similar warming and cooling trend and I'm pretty sure our rovers don't put out that much CO2.
In the 70's there was a panic about global cooling and the imminent ice age. Should we have acted as some suggested, by spreading black soot on the ice caps to melt them and prevent the world from freezing over.
Perhaps we should continue to study it before we do something ridiculous
TRENT! First I'd like to say that I liked Erik's comments. Second, seeing how there is irrefutable conclusive evidence that the earth is getting hotter as a direct result of how humans are treating it, and seeing how there is irrefutable conclusive evidence that man is not responsible for the earth's temperature, I want to focus on each sides motives.
One side has this mentality: lets live our lives and respect the earth, do what we have been doing, being mindful of the earth. God gave us minds to better our lives even if we chop down a few trees. We can grow some more trees."
The other side has these thoughts: "HOLY FETCH the earth is going to be under water! The polar bears will be extict! We are all going to die from these hurricanes if we don't do something! I can make huge amounts of money if I get people to belive these things and sell the things that make the gullible people belive that they are making a difference."
With all the alarmists out there lets think about why they say the things they say. Is it because they are concerned for penguins and polar bears or they just want to make a buck? I have nothing against these people wanting these good things but don't blame it on global warming.
Lets cool our jets just a little bit. Take a step back and understand that this global warming idea is similar to Cancer prevention and cures. Depending on what evidence you look at you can make your point.
Kristen, I would actually love to talk to you and Erik about this in person. You bring up good points. I don't disagree that sun spots contribute to the earth getting hotter. But the data showing that the earth is getting conclusively warmer because of mankind's activities should not be completely disregarded because naturally occurring phenomena influence the earth's temperature also. I am actually not defending the hockey stick graph because it has its weaknesses. But the overall trend of the earth's temperature is definitely increasing. Even though CO2 levels are only 3.5% of greenhouse gases, rapid deforestation, ocean acidification, and record CO2 production logically could make a noticeable change.
You also raise a concern that because we were wrong in the 70s with global cooling, then we shouldn't believe the current reports. Fool me once, shame on you; fool me twice, shame on me, right? Basically you've been burned by predictions in the past, and you are hesitant to believe them now. I've got two words to say to that: Hand test. Back in the early 1900s, a stellar judge by the name of Learned Hand coined an economic formula called the Hand test. This test balances the probability of some harm happening with the cost of preventing such harm. If indeed we are on track to suffer the consequences of global warming, and the effects of "continu[ing] to study it" would be disastrous, then how much cost would it be on each of us to prevent that. Would it be that bad to ditch driving the Hummer to church on Sunday, or replacing inefficient technology in favor of green energy? I think the clear answer is that the minor inconveniences that we would experience to avoid a potentially bad situation is a no-brainer.
Graden - I welcome you to my blog and hope you will continue to comment in the future. My main motive with this post is not to be Al Gore, but to show that there are better data out there in support of global warming. I really doubt that there is "irrefutable conclusive evidence that man is not responsible for the earth's temperature." How bad the consequences will be is definitely up for debate, but the research shows that mankind is contributing to earth's increased temperature. I'm not trying to be alarmist, but people naturally don't like to change. Sometimes you need to wake them up to the harsh reality. Sure we should question people's motives. I would love for you to share how people would profit off of going green. Obviously if you are in the business of renewable energy, you would make money off people going green. However, I'm going out on a limb to say that the majority of scientists who believe that global warming is happening are not all working for solar panel companies. They are probably just doing their jobs as scientists: collecting and analyzing data, and making conclusions. Maybe these scientists have ulterior motives, but I think the burden of proof is on you to show that. Most of them are just scientists for Pete's sake! I question the motives of people who refuse to believe global warming is happening. Big corporations that are polluting and destroying the earth would lose profits, so of course they have an interest in not adopting cleaner, more efficient practices.
Richard S. Lindzen is the Alfred P. Sloan Professor of Meteorology at the Massachusetts Institute of Technology
Dr. Lindzen has clarified numerous times that the matter of “global warming” is unsettled in the academic community. In a recent article he outlined the problems with the assumption of global warming from a scientific point of view. He starts by explaining the simple version of the “greenhouse effect” does not really hold true on our planet. “As it turns out, if there were only radiative heat transfer, the greenhouse effect would warm the Earth to about seventy-seven degrees centigrade rather than to fifteen degrees centigrade. In fact, the greenhouse effect is only about 25 percent of what it would be in a pure radiative situation. The reason for this is the presence of convection (heat transport by air motions), which bypasses much of the radiative absorption.”…“One consequence of this picture is that it is the greenhouse gases well above the Earth's surface that are of primary importance in determining the temperature of the Earth. That is especially important for water vapor, whose density decreases by about a factor of 1,000 between the surface and ten kilometers above the surface. Another consequence is that one cannot even calculate the temperature of the Earth without models that accurately reproduce the motions of the atmosphere. Indeed, present models have large errors here--on the order of 50 percent. Not surprisingly, those models are unable to calculate correctly either the present average temperature of the Earth or the temperature ranges from the equator to the poles. Rather, the models are adjusted or "tuned" to get those quantities approximately right.” He also explains that the original idea that the CO2 levels will double in the next 20 years is being reconsidered with newer data. It will likely not double for over 100 years at our current rate, which is also fortunately falling. There is also reason to doubt the levels of CO2 will do much anyway. “There is ample evidence that the average equatorial sea surface has remained within plus or minus one degree centigrade of its present temperature for billions of years, yet current models predict average warming of from two to four degrees centigrade even at the equator. It should be noted that for much of the Earth's history, the atmosphere had much more carbon dioxide than is currently anticipated for centuries to come. I could, in fact, go on at great length listing the evidence for small responses to a doubling of carbon dioxide; there are space constraints, however.” I am posting these comments by Dr. Lindzen not to prove that there is no Global warming, but rather that the issue is not concrete. Like anything in science it is hard to make reliable conclusions on extrapolations. I believe, however, that our culture needs to change its habits to be more conservative and take care of what we have been given stewardship over. There are more concerning and pressing numbers from a biological standpoint of which you are well aware from our Evol Bio class. We should be using less, wasting less, and DEFINITELY working to preserve and protect our environment. I am, however, a little offended that this issue has been so politicized and used as a stick to beat peoples opinions into line. Your data are compelling but not conclusive, and politicians are claiming that if you are skeptical you are archaic and ignorant. I have other data that say otherwise, but I also think that change toward a more sustainable and cleaner future is never a bad thing.
Here's a link or two if you are curious.
http://www-eaps.mit.edu/faculty/lindzen/PublicationsRSL.html
http://www.cato.org/pubs/regulation/regv15n2/reg15n2g.html
Andrew, great comment. Also, welcome to my blog. I echo your regret that climate change discourse has been so politicized. What I want to make clear is that the initial tone in my blog was perhaps wrong. I do not want to paint anyone who doesn't believe that global warming is happening as ignorant or archaic. Just because the majority of scientists have come to a consensus on things, they are not automatically right. Take plate tectonics, or a number of other scientific breakthroughs. It is possible for the consensus to be wrong and for a paradigm shift to occur. It is cheap to debate on anything other than the merits of the debate. Since your comment, I have spent time checking out perspectives of Richard Lindzen and Michael Crichton (yes, the Jursassic Park guy). There are legitimate opposing points out there, but they are wrong and let me explain why.
You quote extensively from a 1992 article. In the last 17 years, you know as well as I that a lot more data has been collected. I mean we're talking about a time when there was no internet as we know it! Just because the ideal “greenhouse effect” conditions don't work perfectly for our earth due to convection, it doesn't mean these factors haven't been taken into consideration in present models. Even if the greenhouse effect is only 25% of what it would be in a purely radiative situation, that still leaves open the reality that the 25 percent effect can affect the temperature of our globe in a major way. Another thing I want to stress about incorrect predictions in the past – science is not perfect. Make no doubt about it, we make incorrect predictions all the time. But I feel like previous incorrect predictions have hardened many people today in believing that present-day, more accurate predictions could never be correct. Yes, let's be skeptical, but let's also realize that models have improved a lot.
The fundamental question that we are asking here is “is mankind causing global warming?” That question is very loaded so I think it is best to split it up into smaller, more manageable chunks. If anyone wants to debate these individual points, let's do it!
Is the Earth getting warmer? It's getting warmer. See above data.
Is the greenhouse effect real? It's real. How much it affects the temperature of the earth is under debate, but the more greenhouse gases, the more conduction of heat. Andrew, just because one intelligent scientist believes that “there is reason to doubt that the levels of CO2 will do much anyway,” I find it hard to believe that you believe this also. There is simply too much data that shows what CO2 does as a greenhouse gas and too much unnatural change going on in our world to believe otherwise.
Is CO2 a greenhouse gas that is being increased by man? Yes, refer to the above data that there is more CO2 now than ever. Also, MIT released the results showing that a new surge of greenhouse gases ended a leveling of greenhouse gases. Methane levels “have more than tripled since pre-industrial times, accounting for around one-fifth of the human contribution to greenhouse gas-driven global warming.”
Would we expect this warming to have an effect? We would. Major present-day models project an increase of temperature. I would be very interested in seeing one model that does not show an increase in the temperature of the earth. The increase in temperature would change water levels, disrupt crop production, change ecosystems, and possibly result in disasters of Al Gore-ish proportions (although I don't think our situation is that bleak).
Do human beings in general affect the climate? We have a long history of affecting the earth and its climate. The earth doesn't magically repair all that we do to it. Many of the things we do to the environment have irreparable consequences and the sad reality is that mother nature doesn't always bail us out. We must live with our consequences.
From all the comments I've gotten, the message is clear that whatever the truth about global warming, we should take care of our earth. Then let's do it.
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