Given the ridiculous strings of comments we receive here on CleanTechnica from time to time regarding global warming (claims that it's not happening or isn't caused by humans), I thought I should share some important global warming information with you all (information I hope will help you to find some clarity on this issue and will help you in such discussions when you find yourself in the midst of them).

While these commenters are mostly (or probably entirely) just "trolls" (people posting "inflammatory, extraneous, or off-topic messages in an online community, such as an online discussion forum, chat room, or blog, with the primary intent of provoking readers into an emotional response or of otherwise disrupting normal on-topic discussion") who come in from other sites, I think it's important our readers know some basic facts about global warming (since it is a, if not the, leading driver of cleantech globally). So, below is a repost of a recent article I wrote on sister site Planetsave explaining how we know global warming is caused by humans.

First, though, I've got a few other things to share. (Mind you, though, you can often discuss the matter for days with a troll without them budging in the face of scientific facts, so don't hold your breath...).

Here are some links to other posts that I think are useful ongoing resources:

On common climate science myths promoted by trolls:

1. 119 One-Liners to Respond to Climate Science Myths
2. Global Warming Videos (Best, Funniest, Most Inspiring)

On the false scandal referred to as "climategate":

(Short summary: Truthfully, it was a scandal, as emails covering the course of over a decade were stolen and pieces of them were published out of context in an effort to frame the scientists. While at least 7 independent evaluations have determined there was no misconduct in the scientific work of the researchers and their conclusions are as sound as ever (or even more so), many global warming deniers still claim that there was misconduct, and I'm sure many confused citizens who don't follow the issue still think so, as well.)

1. Yes, Climategate was Science Denier B.S.
2. The Real Climategate Crime
3. Climategate: One More Investigation, Still No Basis for Accusations of Misconduct
4. Climategate Scientists Vindicated by Inquiry
5. Mann is Off the Hook, So Let's Look at the Real Crime (Video of Mann)

Also, it's worth noting that a recent study by a leading global warming skeptic and professor of physics, Richard Muller, and funded by some major fossil fuel interests (i.e. the Koch brothers) to "check the work" of thousands of climate scientists found essentially the exact same warming trend as the scientists Muller was "skeptical" of. He has acknowledged this and, thankfully, the mass media has reported on it. But global warming deniers who were once in love with Muller and the project have now turned on him. In the graph below, Muller's study is the one with the black line titled Berkeley:

More on that:

1. BEST Study (Climate Science Skeptic Study) Finds Global Warming is Real - Global Warming Deniers Are Pissed (What's New?)
2. Curry Lost in Denial (& Global Warming Still = More Snow)

If you want to see who else has supported the conclusions of climate scientists (and who hasn't) here is a handy chart:

And, now, a short piece on global warming and how we know it's being caused by humans (some of the reasons why all of the scientific bodies above support this climate science "consensus"):

Yes, Global Warming is Real AND Caused by Humans

By Zachary Shahan

Nothing surprising here, but with a global warming skeptic that deniers were absolutely in love with a few months ago (Richard Muller) finding that the world is warming in his Berkeley Earth Surface Temperature study (BEST), the out-right deniers have kicked him out of their cult and are also claiming that his study was useless. Just a reminder, this is what leading global warming denier Anthony Watts wrote before the results were out:

I'm prepared to accept whatever result they produce, even if it proves my premise wrong....the method isn't the madness that we've seen from NOAA, NCDC, GISS, and CRU....That lack of strings attached to funding, plus the broad mix of people involved especially those who have previous experience in handling large data sets gives me greater confidence in the result being closer to a bona fide ground truth than anything we've seen yet. Dr. Fred Singer also gives a tentative endorsement of the methods....Climate related website owners, I give you carte blanche to repost this.

Now, with the results out and the media actually posting feature stories on the fact that we now know (as if we didn't before) that the world is warming, fossil-fuel front group the Heartland Institute is out trying to confuse people again....

James Taylor (no, not that James Taylor), senior fellow for (anti-)environment policy at the Heartland Institute, has a completely inane op-ed published in Forbes this week that essentially says: "Oh, we knew the earth was warming - no one denied that - we just don't know if it's from humans or how much it will warm in the future." Looks like deniers are finally dropping their first line of denial, but it's of little, little, little surprise that they're still trying to stop us from acknowledging that the warming is human-caused and acting to stop it. (I mean, that is his job after all. He works for the fossil fuel industry, and though he is essentially working to murder countless people who will die from global warming inaction, he is dutifully doing his job.)

But back to the inane arguments, just in case you don't follow the science enough to know that the claims are out of this world:

Humans Cause Global Warming

Just as it's been known for decades that the globe is warming, it's also been known for decades that humans cause it. But over the course of these last decades, the evidence has grown so strong that nearly ever (if not every) overarching scientific organization in the world has stated this is the case. No, not just all those career climate scientists, but overarching bodies evaluating the work those scientists have done.

The Washington Post actually published a great op-ed on this part of the story this week.

Broadly speaking, here are two reasons why the Earth could be warming up. Either more heat is reaching the Earth's surface, or else less heat is escaping out into space. On the first, there's no evidence of a significant increase in heat reaching the earth. True, solar activity can shift from year to year. But satellite data shows that total solar irradiance has declined slightly in the past 30 years, even as the planet continues to warm. Scratch that theory.

So something's keeping the heat in. Physicists have long known from lab experiments that greenhouse gases like carbon-dioxide can absorb certain frequencies of infrared radiation and scatter them back toward the Earth. We also know these gases are increasing in the atmosphere, largely due to the burning of fossil fuels (checking this involves some fairly straightforward chemistry). And, indeed, satellite data has shown that less and less infrared in the specific frequencies in question is escaping out into space, while more is bouncing back to the Earth's surface. There's your culprit.

Now, that's the quick and simple, and for those of you not satisfied with the quick and simple, here's more below (images after the list):

I posted on 10 indicators showing that humans are causing global warming a long time ago, mostly reposting the great work of folks over at Skeptical Science. Here are the "fingerprints" proving the case (some of the images are for items listed, some are additional points):

1. CO2 has, "coincidentally," been increasing at about the same rate as global temperatures (odd, eh?).
2. It's clear from measuring the type of carbon building up in the atmosphere that it is carbon from burning fossil fuels. (Manning 2006)
3. Oxygen levels are declining just as CO2 is increasing from the burning of fossil fuels.. to a degree that matches like two neighboring puzzle pieces (in other words, exactly as one would expect of one theorized that the atmospheric changes are due to the burning of fossil fuels). (Manning 2006)
4. Hundreds of years of coral reef measurements show a sharp rise in carbon from fossil fuels, matching the increased burning of fossil fuels by humans in recent years. (Get the picture? The puzzle pieces all fit together. Surprising! Unless you understand the basic fact that our burning of fossil fuels is having an effect on the atmosphere and the oceans.) (Pelejero 2005)
5. OK, so we know CO2 from the burning of fossil fuels is rising. Next is to show how this influences the climate. From the post linked above: "Satellites measure less heat escaping out to space, at the particular wavelengths that CO2 absorbs heat, thus finding 'direct experimental evidence for a significant increase in the Earth's greenhouse effect'. (Harries 2001, Griggs 2004, Chen 2007)."
6. It has also been confirmed that that heat not reaching out to space is being sent back to Earth. (Philipona 2004, Wang 2009). And, in particular, at the wavelengths of CO2! As a climate scientist reports: "this experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming." (Evans 2006).
7. "Greenhouse effect warming" should have specific fingerprints of its own. One of those should be that the Earth should warm faster at night than in the daytime. Confirmed. (Braganza 2004, Alexander 2006)
8. And that the upper atmosphere (aka stratosphere) should be cooling. Confirmed. (Jones 2003).
9. The tropopause - the line between the upper atmosphere (stratosphere) and the lower atmosphere (troposphere) - should also be rising. Confirmed. (Santer 2003).
10. And for the last piece of evidence, I'll quote the story linked before this list again: "An even higher layer of the atmosphere, the ionosphere, is expected to cool and contract in response to greenhouse warming. This has been observed by satellites (Laštovi?ka 2006)."

Now, the only way someone could deny that the world is warming due to the greenhouse effect (which is caused by humans burning more fossil fuels) is by ignoring the evidence (lying), not looking into and finding the evidence, or being so incapable of understanding science that they don't understand the evidence. I'm not going to conjecture which one of those Taylor is, since I don't know him personally, but he is clearly one of them if he thinks global warming isn't caused by humans.

How Much Will the Earth Warm?

Now, for his second point, that we don't know how much the world is going to warm, that is true, of course. However, the climate scientists warning us that it is going to be catastrophic warming if we don't change course soon have been tremendously more accurate in their projections for decades than global warming "skeptics" like Taylor. However, even they have been underestimating the warming and effects in some cases!

No, there is no comfortable reality where "this is not happening and there's no evidence the future won't be catastrophic if we don't change course." Sorry, Taylor. No one wants to be facing this challenge. But we are. Hiding under your blankets when your house is on fire isn't going to help anyone. Telling your wife and children there is no fire in the house isn't going to help anyone. It's only going to make the situation that much worse.

Image Credits: Climate Progress & Skeptical Science (first eight); Union of Concerned Scientists (last one)

Source: Clean Technica