The Globe is Warming, our Planet is Changing, Here’s Why

By Tom Yulsman | September 27, 2013 12:11 pm

Carbon dioxide in the mid-troposphere, as mapped by the Atmospheric Infrared Sounder, or AIRS instrument, on NASA’s Aqua satellite. (Image: NASA Earth Observatory)

A long-awaited report from the Intergovernmental Panel on Climate Change was officially released today. The summary for policy-makers opens with this thumbnail sketch of how our planet has changed:

Warming of the climate system is unequivocal, and since the 1950s, many of the observed  changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.

While the rise in temperatures has leveled off in recent years…

Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850…In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years (medium confidence).

And then there’s the punchline that is being widely reported today by media around the world:

It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

In that coverage, you’ll see a plethora of graphics from the IPCC report itself. And I’m sure I’ll be posting some of that in days to come as I have time to dissect the report. But for now, I thought I’d go with something different — a global map of carbon dioxide concentrations in the atmosphere, published yesterday by NASA’s Earth Observatory. It’s the graphic up top.

When the IPCC says “human influence” has been the dominant cause of climate change, they’re talking in large measure about carbon dioxide — the greenhouse gas that is having the greatest impact. (But others are certainly important too. Methane, for example.) And the map, based on data from the Atmospheric Infrared Sounder, or AIRS instrument, on NASA’s Aqua satellite, shows how it was distributed around the globe during May in the troposphere, the part of the atmosphere where most weather happens.

This is when the concentration of carbon dioxide in the atmosphere nudged above 400 parts per million for the first time in at least 800,000 years, and perhaps as many as 2.5 million years.

As the map shows, CO2 is not distributed evenly. There was more above the Northern Hemisphere than in the south. NASA attributes this to the measurements being taken in May, when seasonal plant growth — and thus removal of CO2 from the atmosphere by those plants — had not yet kicked into high gear. And since there’s more land area, and thus more plants, in the north than the south, this region dominates the seasonal CO2 pattern.

But that’s probably only part of the story. The other part is that most CO2-emitting industry, cars, etc. are located in the Northern Hemisphere.

One other thing to consider: Since May, CO2 concentrations in the Northern Hemisphere have dropped a bit below 400 ppm. This has occurred as Northern Hemisphere plant growth during the warm season has pulled some of the gas out of the atmosphere. Here’s the latest data from NOAA’s Earth Systems Research Laboratory:

Week beginning on September 15, 2013:     393.48 ppm
Weekly value from 1 year ago:     390.74 ppm
Weekly value from 10 years ago:     373.01 ppm

According to Pieter Tans of ESRL, it will take awhile longer for the global average of CO2 to increase to 400 parts per million — perhaps not until 2016.

Stay tuned for more from the IPCC report…

  • Eric Gallant

    What if a warmer planet is good? There’s a lot of evidence showing that warmer climates are better for vertebrate biodiversity and much better for plant life.

    • Tom Yulsman

      Tell it to the Bangladeshis, the Maldivians and the Floridians.

      • Eric Gallant

        Tell it to the Canadians who enjoy more arable land, easier access to natural resources and navigable shipping lanes. (Florida…really? I was just there. Florida is fine.)

        • Tom Yulsman

          As their country disappears, I’m sure the 154.7 million people of Bangladesh will be so happy to know that Canada will be growing more wheat.

          As for Florida, it is not fine. Sea level rise is already exacerbating a number of significant problems. For example, salt water is intruding into aquifers that millions of residents depend on for their drinking water. During particularly high tides, sea water spews from Miami sewers. And the city is already raising the level of some streets that flood regularly during high tides and storm surges. Officially, they do not call it “adaptation to climate change.” But Miami officials have told me that this is exactly what it is.

          Lastly, concerning your comment that climate change could be good for “vertebrate diversity”: What a smug and misanthropic comment that is.

          • Eric Gallant

            This is what’s so tedious about trying to talk about this subject. All I did was ask a question and suddenly I’m a smug misanthrope. Try to maintain a smidgen of objectivity Tom.

            Have you even read the report? The IPCC backpedaled from previous predictions for sea
            level rise. Now they predict 1.5 to 2 feet over the next 100 years. That’s problem. However, sea level rose 1 foot over the last 100 years and we managed to deal with that. I’m pretty
            confident that even the poor Bangladeshis can figure out how to deal with another 18 inches over the next 100 years.

            The planet is in an interglacial period. Ice will melt, seas will rise, habitats will change. The
            last interglacial was warmer than this one and temperate zones were larger and plant and animal life were more diverse. That was a perfectly normal warm period and a climate very conducive to life…very similar to this one. Wake up and smell the Holocene. It’s not all doom and gloom.

          • jh

            When you refer to “sea level” problems in a given area or locality, you’re not talking about global sea level rise, you’re talking about relative sea level rise. Of course you know that relative sea level rise is a combination of local subsidence, local sea level and global sea level.

            At least part of the salt water intrusion problem in Florida aquifers is from humans sucking out the fresh water and drawing in the salt water. This problem would be occurring regardless of global sea level rise. It would be interesting to know the relative contributions of the two: I suspect GW withdrawal is very important.

            A large portion of Florida’s southern panhandle is subsiding because soils have been drained for agriculture, causing the organics in those soils to decompose and structurally collapse.

            Reducing CO2 emissions won’t impact either of these problems, which I suspect are at least as significant if not more significant than AGW-related sea level rise. And I suspect that’s the case over most of the world: CO2-related problems are equal or smaller in scope to other development-related problems, which will continue to be problems as long as humans exist.

            Reducing CO2 emissions is a feel-good goal. The targets that would really matter are impossible – IMPOSSIBLE – to hit. People that keep pushing for this stuff are like the Republicans trying to kill Obamacare: out of touch and unable to accept the simple math that shows they can’t win.

            Time to move on.

  • Buddy199

    Although there is still some question about the parameters of the problem even according to the IPCC, there remains the question of what to do about it. Conservation, wind and solar even with major advances in technology would still only provide a fraction of the energy needed to run a modern world economy. With that in mind, the only non-carbon source of electricity conceivable as a large scale replacement for fossil fuel is nuclear power. Sure. we’d like everybody in the world to ride a bike and bring a cloth bag to Whole Foods but, realistically, the choice comes down to what’s technically feasible: either fossil fuel or nuclear until some as yet undeveloped technology such as fusion is practical and available.

    • Tom Yulsman

      Obviously, a key question. A colleague of mine has calculated that if we want to decarbonize by the year 2050 while also providing for a decent standard of living for everyone, we’d have to build electrical capacity equivalent to a nuclear power plant every week.

      We’re obviously not going to do that. So we need to be talking more about adaptation (which would be necessary even if we magically eliminated carbon emissions tomorrow), while we also take sensible steps to reduce carbon emissions. We don’t have to have the grand solution now. But we do need to get started.

      • Buddy199

        We’ve only got so many cards in our hand technologically as I can see. Also deal with the aspirations of several billion people who don’t want to wait to enter the middle class. What would you suggest is a realistic solution?

      • Dana Ritschel

        Everyone talks about new tech the need for more tech. I’m not a world famous climate scientist but why not use nature to solve the problem? Plant more freaken trees!

  • Mark Curtis

    There are two things I would like to say about solutions to our looming problem.

    First, I cannot recall hearing about any human population anywhere, at any time in history, who have banded together taking proactive action to stop a problem that is merely “looming.” It seems to me that humans must be experiencing death and pain on a large scale TODAY in order to take action. Psychological inertia is a wonderful trait 99% of the time. It keeps us from expending energy chasing “maybe’s” and “probably’s”. And, there is always a group of people who “saw it coming,” who have the satisfaction of saying, “if we had just _____ when we had the chance.” But, by and large, cultures and societies and habits are inert. Just think how different history would be if the Romans had all gotten together and said, “We need to get our act together before our entire empire falls apart. It will take sacrifices from every citizen, rich or poor, of every social standing.” What if the first Native Americans to meet the white “explorers” had assembled and said, “We think that this is a disaster looming on the horizon. We must all come together and stop any of the white men before they set foot on our shores.”?

    Second, when we do start experiencing an actual dread of something terrible, and we see pain and death approaching, we are more than likely going to try to protect our own and hopefully the problem won’t come to our house. Those in “higher” economic circumstances or more “defendable” social and physical situations will throw the “lesser elements” of society under the bus. Any “sacrifices” made by the upper class will be human sacrifices of those less fortunate.

    Yes, I understand that there are always exceptions to the rule, however, humans have a long history of ignoring a problem until it is upon them and then making sacrifices that usually involve the politically and economically weak taking the brunt of those sacrifices.

    My conclusion?
    Ain’t nothin’ gonna happen until the fat cats start to feel the burn.

    • Buddy199

      Long story short: we’re boned.

  • Don Thompson

    Lets see now, how many of these IPCC reports will it take to convince everyone that they are not about science but about political science and control. Would someone care to point out one forecast in all the reports produced so far that has occurred, (please, exclude manufactured data) or are we going to have to wait for the next 100 years to convince humanity that what they have witnessed is the biggest HOAX ever perpetrated on mankind.

  • Brad Haugan

    Hydra Renewable Resources creates re-newable energy, clean water, potable water & food. We recycle 100% of municipal solid waste and waste water sludge. Adopting our technology, a city of 300,000 will reduce its output of GHG by 125,000 TPY, all accomplished in a robust profitable invironment.

  • Samriti Rai

    #TomYulsman The map that displays carbon dioxide shows that the North Pole and the equator share the same carbon dioxide in the atmosphere. What does that mean or show?



ImaGeo is a visual blog focusing on the intersection of imagery, imagination and Earth. It focuses on spectacular visuals related to the science of our planet, with an emphasis (although not an exclusive one) on the unfolding Anthropocene Epoch.

About Tom Yulsman

Tom Yulsman is Director of the Center for Environmental Journalism and a Professor of Journalism at the University of Colorado, Boulder. He also continues to work as a science and environmental journalist with more than 30 years of experience producing content for major publications. His work has appeared in the New York Times, Washington Post, Audubon, Climate Central, Columbia Journalism Review, Discover, Nieman Reports, and many other publications. He has held a variety of editorial positions over the years, including a stint as editor-in-chief of Earth magazine. Yulsman has written one book: Origins: the Quest for Our Cosmic Roots, published by the Institute of Physics in 2003.


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