Is global warming really happening?

The controversy among scientists isn’t whether global warming is happening.  There is just about universal agreement across the board that it is.  The sea level around New York, for instance, is a foot higher than it was 100 years ago, which is one of the reasons why the storm Sandy was so devastating.  And a recent report bringing together what up to now had been disparate measures of the  polar caps show that ice is melting three times faster than it was just 20 years ago.  Some scientists now think that temperatures could increase by as much as 6 degrees  Celsius instead of their 4 degrees maximum expectation last year.

The real controversy isn’t whether changes are occurring.  The controversy is the cause of this environmental change.

Is it, as some climatologists think, a natural variation around the norm that occurs in the weather over the years?  We have, after all, experienced severe droughts before.  Floods are not a new phenomenon, nor are mega-storms, or occasionally exceptionally hot summers or warm winter temperatures.  Europe even experienced a “little ice age” as recently as the 17th century.

Or is human activity responsible for the increase in greenhouse gases that are changing our weather?  Before the industrial  age began two centuries ago, greenhouse gas equaled 278 particles/million.  Since then, greenhouse gases in the atmosphere have increased by 40% to 391 particles/million.  This is the highest it’s been in more than 15 million years.

Again, no serious climatologist claims that greenhouse gases do not contribute to global warming.   But some scientists think that we do not have enough long-term data to jump to dooms-day conclusions.  They claim, quite rightly, that cutting down on greenhouse gases by using less fossil fuels and more renewable sources of energy may very well slow down the global economy, leading to increased poverty for millions and the deprivations that go with it.  Better they say, to wait and see.

Wait-and-see is a recipe for disaster for the majority of climatologists who think the data already is increasingly pointing to human activity as the cause of global warming and destructive environmental changes in Earth’s oceans and on land.  They point out that once the data is unequivocal enough to convince even the most skeptical, it will be too late.  The melting of the Arctic ice cap  is already accelerating;  in twenty years time we will not be able to slow the process even if we don’t add another particle of greenhouse gases to the atmosphere.

So this is the question:  should we act now even when there is still some modicum of doubt in order to try to avert what might be environmental changes that all agree would be catastrophic for life as we know it?  Is it worth the mega-effort and expense that reducing our fossil fuel use will demand?  Or should we be careful, keep watching, and trust that should things get worse, we will be able to figure out how to handle it intelligently when it happens?

To some extent, we are in the difficult position of having to answer the question – even by the default option of doing nothing – before we have all the information.  But what we decide will have huge implications for our children and our grandchildren.  Even if we don’t know for sure what those implications are.



About Terry Sissons

Terry Sissons is the author of The Big Bang to Now: All of Time in Six Chunks, and this blog is a dialogue about the universe and what’s happened in the last 13 billions years.
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6 Responses to Is global warming really happening?

  1. Arno Arrak says:

    “The controversy among scientists isn’t whether global warming is happening. There is just about universal agreement across the board that it is.”

    Oh really? Speak for yourself, not for me. You will find my reasons for not believing this in the book “What Warming?” available on Amazon. Fact is that there is no warming now and there has not been any for the last 16 years while carbon dioxide relentlessly increased. I get this from the official record of global temperature put out by the Met Office in UK. Carbon dioxide is accused of warming the world by the greenhouse effect but it is pretty obvious by now that it isn’t working. In 2007 IPCC used the greenhouse theory to peer into the future and predicted that global warming in the twenty-first century shall proceed at the rate of 0.2 degrees Celsius per decade. We are now in the second decade of this century and there is no sign whatsoever of this predicted warming despite a steady increase of atmospheric carbon dioxide. Traditional fate of scientific theories that make false predictions is to be consigned to the trash heap of history. The greenhouse theory of warming has made such a false prediction and therefore it belongs in the trash heap of history. It follows that all its previous predictions of warming are also false. Since these predictions have been used as justification for passing emission control laws these laws have been passed under false premises. Now they all must be voided. I have a suggestion for Doha conferees: forget your agenda and start thinking of how to nullify all these laws deceptively foisted upon the unsuspecting public.

    • Thank you, Arno, for taking time to write such an informed comment on global warming. I appreciate especially that you are trying to examine the evidence rather than relying on name-calling – a temptation to which I fear both sides of this debate have too often succumbed. It’s the “don’t distract me with the facts,” approach that is ultimately so determinedly ignorant.

      I would also say that, although I am not a climatologist, I am trained as a scientist, and appreciate that we simply do not have sufficient data yet for either side to prove its case conclusively. I am not convinced that shifts in El Nino and his sister La Nina, irrespective of greenhouse emissions, fully explains our current weather patterns. Neither am I, however, convinced that global warming is real simply because “most” scientists say it is. “Most” experts believed for thousands of years that the world was flat. As little as 200 years ago, eminent scientists believed that the universe was no more than six thousand years old. I’ve lived long enough to know that “most” scientists can be wrong.

      But as you may very well appreciate, the question of the role of CO2 emissions in the environmental changes we are observing – the increasing speed at which the arctic ice cap is melting, the acidification of the oceans, the decreasing yield of agricultural land, even the changing Nino & Nina patterns – is not absolutely clear. We just don’t have enough data yet to know for sure.

      And that’s the scary part, as I see it. Based on the data, I lean in one direction, you lean in the other. But decisions have to be made based on what we know — which is precious little. It’s just that it might matter so very much to the next generation.

  2. Henk Meevis says:

    It seems clear that we know that up and down climatic condition changes have happened over periods covering millions of years on earth. My question is; what did we do at those times to accommodate ourselves in order to cope with ice ages and super high temperature periods? My answer is; we did nothing, we outlived such adverse conditions by addapting. Sure, we are burning fossil matter at a great rate and logic teaches us this may effect a particular up or down period, not necessarily limited to temperature swings. But attempting to halt the damage we may have caused could well result in adverse reactions we cannot possible predict in advance.

    • I appreciate your point, especially your worry that by attempting to halt the damage we may have caused, we could make matters a great deal worse. I agree. Some of the ideas I have read about scare me because they could very well go horribly wrong and yet be irreversible.

      On the other hand, we humans have not lived through millions of years on earth. We have been here, at most, 250,000 years. That means we have not lived on this planet during its warmest periods. Technically, we are still in what is called an “interglacial period” of what is an ice age that began about 2 1/2 million years ago. We first appeared in Africa, where, relative to today, our population was small. In addition, it was reduced from several hundred thousand to as little as 20,000 worldwide after the climatic devastation resulting from the Toba Supervolcano 74,000 years ago. We survived, and with ingenuity and care, I hope our species will survive for a very long time yet to come.

      But we are not immune from extinction. Thousands of other mammals are becoming extinct today as a result of changes in the environment. Some of these changes are a result of humans – of our cutting down forests,or of our polluting rivers and lakes, etc. The great drought of almost the entire food-producing prairie lands in America in the 1930’s is recognized as man-made.

      It’s a tough problem. I do not believe it is without hope. But I do think it is potentially serious. I would be interested to hear your further thoughts – especially if you disagree, and why. I’d love to be convinced!

      T Sissons

  3. Nathan Manning says:

    Arno – I dont think you can make statements and go as far as saying ‘fact’
    If you have scientific data which supports your bold statements, then please share this with us. This is not a free advertising agency for your book. Climate change whether it is happening or not, the polar ice caps are melting at an alarming rate regardless what you think. I think it is fair to say that the majority of scientists across the Globe are in agreement that climate change exists! Perhaps though, there is uncertainty over the rate at which it is effecting us.

    • Hi Nathan – Thank you for your comment. I agree that the majority of scientists are increasingly convinced that climate change is happening. I also think it’s a good idea to call it “climate change” rather than “global warming,” because for some of us, the change in the gulf stream means much colder winters and wetter summers. For the midwest United States, it might mean more droughts. For coastal areas, and some locations in land, it will mean more flooding. Food and water shortages may increase significantly. So “warmer” is probably not the more critical feature.

      I think the most contentious disagreement, however, is not whether climate change is occurring but why. Is it due to human activity, specifically our greenhouse gases? or is this merely a manifestation of the “normal” variation of weather patterns over the years? The reason, of course, this is so critical is because if climate change is due to human activity, then it is we who have to do something about it or face our own destruction due to our failure to act. But if it’s normal weather variations over which we have little control, then the effect of any changes we might make will be minimal.

      I think the evidence is strong enough for the world to act even if it is not absolutely conclusive. Because if we wait until the evidence is absolutely conclusive, it will be too late and our children and grandchildren will be trying to survive on a planet we have badly damaged.

      I’d be interested to know if you agree.

      Terry Sissons

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