climate

The following editorial was published today by 56 newspapers around the world in 20 languages including Chinese, Arabic and Russian. The text was drafted by a Guardian team during more than a month of consultations with editors from more than 20 of the papers involved. Like The Guardian most of the newspapers have taken the unusual step of featuring the editorial on their front page. The Guardian editorial is free to reproduce under Creative Commons.

Copenhagen climate change conference: Fourteen days to seal history’s judgment on this generation

Today 56 newspapers in 45 countries take the unprecedented step of speaking with one voice through a common editorial. We do so because humanity faces a profound emergency.

A bigger rise of 3-4C — the smallest increase we can prudently expect to follow inaction — would parch continents, turning farmland into desert. Unless we combine to take decisive action, climate change will ravage our planet, and with it our prosperity and security. The dangers have been becoming apparent for a generation. Now the facts have started to speak: 11 of the past 14 years have been the warmest on record, the Arctic ice-cap is melting and last year’s inflamed oil and food prices provide a foretaste of future havoc. In scientific journals the question is no longer whether humans are to blame, but how little time we have got left to limit the damage. Yet so far the world’s response has been feeble and half-hearted.

Climate change has been caused over centuries, has consequences that will endure for all time and our prospects of taming it will be determined in the next 14 days. We call on the representatives of the 192 countries gathered in Copenhagen not to hesitate, not to fall into dispute, not to blame each other but to seize opportunity from the greatest modern failure of politics. This should not be a fight between the rich world and the poor world, or between east and west. Climate change affects everyone, and must be solved by everyone.

real progress... could only begin with the arrival of President Obama in the White House and the reversal of years of US obstructionism The science is complex but the facts are clear. The world needs to take steps to limit temperature rises to 2C, an aim that will require global emissions to peak and begin falling within the next 5-10 years. A bigger rise of 3-4C — the smallest increase we can prudently expect to follow inaction — would parch continents, turning farmland into desert. Half of all species could become extinct, untold millions of people would be displaced, whole nations drowned by the sea. The controversy over emails by British researchers that suggest they tried to suppress inconvenient data has muddied the waters but failed to dent the mass of evidence on which these predictions are based.

Few believe that Copenhagen can any longer produce a fully polished treaty; real progress towards one could only begin with the arrival of President Obama in the White House and the reversal of years of US obstructionism. Even now the world finds itself at the mercy of American domestic politics, for the president cannot fully commit to the action required until the US Congress has done so.

But the politicians in Copenhagen can and must agree the essential elements of a fair and effective deal and, crucially, a firm timetable for turning it into a treaty. Next June’s UN climate meeting in Bonn should be their deadline. As one negotiator put it: “We can go into extra time but we can’t afford a replay.”

At the deal’s heart must be a settlement between the rich world and the developing world covering how the burden of fighting climate change will be divided — and how we will share a newly precious resource: the trillion or so tonnes of carbon that we can emit before the mercury rises to dangerous levels.

Social justice demands that the industrialised world digs deep into its pockets and pledges cash to help poorer countries adapt to climate change, and clean technologies Rich nations like to point to the arithmetic truth that there can be no solution until developing giants such as China take more radical steps than they have so far. But the rich world is responsible for most of the accumulated carbon in the atmosphere – three-quarters of all carbon dioxide emitted since 1850. It must now take a lead, and every developed country must commit to deep cuts which will reduce their emissions within a decade to very substantially less than their 1990 level.

Developing countries can point out they did not cause the bulk of the problem, and also that the poorest regions of the world will be hardest hit. But they will increasingly contribute to warming, and must thus pledge meaningful and quantifiable action of their own. Though both fell short of what some had hoped for, the recent commitments to emissions targets by the world’s biggest polluters, the United States and China, were important steps in the right direction.

We will have to shop, eat and travel more intelligently. We will have to pay more for our energy, and use less of it. Social justice demands that the industrialised world digs deep into its pockets and pledges cash to help poorer countries adapt to climate change, and clean technologies to enable them to grow economically without growing their emissions. The architecture of a future treaty must also be pinned down – with rigorous multilateral monitoring, fair rewards for protecting forests, and the credible assessment of “exported emissions” so that the burden can eventually be more equitably shared between those who produce polluting products and those who consume them. And fairness requires that the burden placed on individual developed countries should take into account their ability to bear it; for instance newer EU members, often much poorer than “old Europe”, must not suffer more than their richer partners.

The transformation will be costly, but many times less than the bill for bailing out global finance — and far less costly than the consequences of doing nothing.

Many of us, particularly in the developed world, will have to change our lifestyles. The era of flights that cost less than the taxi ride to the airport is drawing to a close. We will have to shop, eat and travel more intelligently. We will have to pay more for our energy, and use less of it.

last year for the first time more was invested in renewable forms of energy than producing electricity from fossil fuels But the shift to a low-carbon society holds out the prospect of more opportunity than sacrifice. Already some countries have recognized that embracing the transformation can bring growth, jobs and better quality lives. The flow of capital tells its own story: last year for the first time more was invested in renewable forms of energy than producing electricity from fossil fuels.

Kicking our carbon habit within a few short decades will require a feat of engineering and innovation to match anything in our history. But whereas putting a man on the moon or splitting the atom were born of conflict and competition, the coming carbon race must be driven by a collaborative effort to achieve collective salvation.

Overcoming climate change will take a triumph of optimism over pessimism, of vision over short-sightedness, of what Abraham Lincoln called “the better angels of our nature”.

It is in that spirit that 56 newspapers from around the world have united behind this editorial. If we, with such different national and political perspectives, can agree on what must be done then surely our leaders can too.

The politicians in Copenhagen have the power to shape history’s judgment on this generation: one that saw a challenge and rose to it, or one so stupid that we saw calamity coming but did nothing to avert it. We implore them to make the right choice.

A recent article in the BBC News claims that Global Warming has stopped in recent years.  In fact, they claim, that there has been no warming over the last 11 years.  Meanwhile, CO2 emissions continue to rise, and climate scientists steadily posit that the climate continues to warm due to greenhouse gas emissions.  So what’s the truth?

Some aspects of climate are relatively simple.  For example, we know that when the greenhouse gas concentrations in our atmosphere rise, the planet warms.  We also know that the burning of fossil fuels is causing the greenhouse gas concentrations in our atmosphere to rise.  Even a seven year old can put these two facts together and conclude that burning fossil fuels causes the Earth to warm.

So why, if the science is so clear, is there controversy?  There are two important answers to this question.

First, there isn’t really a controversy.  As a naturally argumentative profession, never will every scientist agree about everything, but in the case of global warming, there is a clear consensus. Yes, there remain a few fringe scientists that grasp at fewer and fewer straws, desperate to deny that mere mortals could drastically alter their own environment in detrimental ways.  But, in the past three decades, every professional scientific society has released a statement that reflects the consensus view that human activity is warming the planet.  If you aren’t one for consensus, stick to the physical principals.  Either way, you’ll converge on a single conclusion.

The second answer is that the climate system is complicated.  This isn’t a cop-out. We are not asking you merely to take our word for something here, nor are we going to point out that some of these global warming deniers are confused.  Rather, we must understand that while the dominant factor that has influenced climate in the past 40 years has been human activity, there are other factors that still play roles in the yearly swings in temperature.  That is one reason why our annual average temperature is not merely on a straight course right off the top of the charts but varies up and down from year to year.  Accordingly, one must look at longer-term trends than single years to see the effects of global warming.  And one must also understand that weather, the instantaneous state of the atmosphere, is very different from climate, the expected patterns of weather.  It is the patterns here that are changing.

Let’s examine the claims from the BBC article.  First, they claim that the climate has not warmed in the last 11 years.  It is often said that the truth is in the eye of the beholder.  If we choose to ignore all of the data from polar regions, which is where the bulk of the recent warming has occurred, we can see that the climate has not warmed very much.  Include the data from the rapidly warming Arctic (with the rest of the planet), and a different picture emerges.  Several global temperature records exist, but the NASA GISS record (below) has the most complete global coverage, especially in the polar regions.  In the most recent part of the record, where data coverage is most reliable, we can clearly see that there is a continued upward trend in temperature (despite the aperiodic year-to-year swings).


Their other claim is that solar forcing is responsible for the decreased warming.  This may be partially true.  Solar output does play a role in our climate and is included in climate models that project our climate into the future.  These models also include climate coolings caused by volcanic eruptions (which are difficult to predict), and other natural factors that are known to influence climate.

When taken alone, without greenhouse gas emissions, these natural influences on climate do not predict the recent or continued warming (see top part of figure below – black line is the actual measurements).  So, the claims made in the BBC article are somewhat true – changes in incoming solar radiation do not forecast a warming climate in the coming decade and may lead to a cooling.  But add that to human-caused (anthropogenic) greenhouse gas emissions (center part of figure below) and the result (bottom part of figure) is still a warming climate.


So, our climate will continue to vary because of natural forcings (solar, volcanic, etc.) and because of natural cycles in the climate system (El Niño and others), but the overall warming from greenhouse gasses is inescapable unless we take action to reduce our emissions and reduce the concentrations of these gasses in our atmosphere.

Today, a new post on Realclimate.org debunks yet another pseudoscientist claiming to have found the cure to all of our global warming blues. Read the article here.

Of all the blogs I read, my favorite and most trusted (and also voted top Science Blog of 2005) is RealClimate.org. One role that they have played in the recent past has been to report on pseudo-science climate reports that regularly seem to take the Internet by storm. They cast these reports in the light of actual science.

This weekend, such a report hit the media, popping up in the Daily Telegraph and the National Review suggesting that a century of climate science and physics should be discounted because of the study of self-proclaimed climate guru Steve McIntyre. In his erroneous study, he took a tree-ring temperature record that has been painstakingly reconstructed from trees in Siberia and demonstrates that if you throw out all of the trees that are sensitive to climate (i.e. the trees that one would want for a climate reconstruction) and replace them with tree-ring records that were discarded in the study (because the trees did not demonstrate a sensitivity to climate), that you do not reproduce the warming signal seen in climate records from around the world.

Fascinating. So, if we throw away all of the valid data (selected using age-old techniques in dendrochronology) and replace them with bogus data (thrown out because they didn't record any climate signal), we find that there is no warming signal in Siberia. And we should be amazed in some way by this?

In actuality, if we threw away all of the tree-ring records, here is what we are left with:

Frankly, all of this pseudoscience does very little to impress me. It's akin to me walking into an optometrist's office during an exam and suggesting that they just continue to increase the magnification on the patient's prescription until they can see clearly. It would not only be a poor suggestion and demonstrate a complete misunderstanding of the world of optometry on my part, but it would be insulting to the optometrist that spent years studying the trade to insinuate that I knew better than they. So, why do non-climatologists so frequently tread on our turf?

The folks at Realclimate might have some answers. At least they seem to have a bit more patience for this than I do. Read more here.

A new study by Halevy et al. published in the Journal of Geophysical Research (Vol. 114, D18112, doi:10.1029/2009JD011915, 2009) uses radiative transfer theory to demonstrate that higher levels of CO2 and other greenhouse gasses in the early Earth and Martian atmospheres limited the amount of infrared radiation that is able to escape the planets' atmospheres. It's a nice result, but not at all unexpected. Read the full article here.

Fig.3C: As CO2 concentrations increase, outgoing longwave radiation (OLR) decreases.

For the tiny portion of the global population that still thinks that Global Warming is a hoax that Al Gore and some liberal scientists are proposing to make a few bucks, I swallow back some harsh words and will try to patiently offer some data for you to peruse. (I will try not to compare you directly to the idealists that still think that the reason that dinosaurs are buried deeper in the fossil record is because they had bigger shovels.)

First, to my friends that claim that the climate is now cooling, I ask you to explain the global instrumental temperature record below. Sure, I have chosen NASA's record, but I could easily have chosen many others -- some that show slightly more or less warming, depending on how exactly you calculate a globally-averaged annual temperature.

(Click image to enlarge)

In 1991, we concluded that the 1980s were the warmest decade on record. In 2001, we concluded that the 1990s were the warmest decade in over 1000 years. What will we say in 2011 about this decade?

Note that while year-to-year temperatures fluctuate more wildly due to natural influences like El Niño and volcanic eruptions, the 5-year average tends to smooth these out. Also note that prior to the passage of the Clean Air Act in the 1970s, aerosols in the atmosphere (which block out sunlight) tended to mask much of the warming, and while you can see an upward trend, the natural cycles of climate still dominated much of the signal. Since the late 70s, the rise in temperature has been much steeper as the aerosols quickly fell out of the atmosphere and the greenhouse signal dominated.

This response is reflected not only in global temperatures (a pretty poor measure of climate, which includes all of the patterns of weather, not just averages and not just temperature), but we have seen reductions in northern hemisphere snow cover and Arctic sea-ice. See figure below from Post et al. (2009, Science 325, 1355, DOI: 10.1126/science.1173113).

One of the patterns that has long been expected from anthropogenic warming is enhanced warming in the polar regions. While we've barely felt the effects here in the mid-latitudes (where we are emitting the most carbon), the high-latitudes have been warming especially fast. It is no surprise that the Arctic has warmed (see below). What is surprising is how fast it has warmed, and how fast the Greenland Ice Sheet has responded to that warming.

This warming manifests not only in surface melt on the Greenland Ice Sheet, but a thinning of the ice and speeding up of outlet glaciers as they move toward the coast. Below is a map of this dynamical thinning derived from repeat laser altimetry. The blue circles (can you see them there??) are areas where the ice is actually thinning a bit. The red are areas that are thinning. The image comes from Pritchard et al. (2009, Nature, 10.1038/nature08471).

Gravimetric measurements of the ice sheet indicate that it is steadily losing mass, ending any debate as to whether mass loss on Greenland is outweighing the increases in accumulation that we expect in a warming climate.

(Click image to enlarge)

Another surprise is how much the interior of Antarctica has warmed. 50 years of measurements reveal a robust warming trend on our southern-most continent.

(Click image to enlarge)

Some of my less-informed acquaintances argue that the Earth is in a cooling trend and that it is all caused by solar radiation. And they are not altogether wrong. We should be in a cooling trend, were it only for natural forcings, like incoming solar radiation (or insolation, for short). The robust warming signal that we have witnessed in the last century puts an abrupt end to a long-term cooling trend in the Arctic. This figure is taken from Kaufman et al. (2009, Science 325, 1355, DOI: 10.1126/science.1173983).

(Click image to enlarge)

So, while insolation in the Arctic is DECREASING, temperatures are INCREASING. This goes against all previous measurements and physics, unless you allow for a greenhouse warming (which is physically ubiquitous). Below, Kaufman et al. show that when insolation is low, temperatures are low. Except for now. Yes, human behavior is having a larger influence on climate than fluctuations in solar output.

So, what does this all mean? Many things. Two that I will share below. First, sea levels are rising. They are rising much faster than predicted. And they will continue to. We will likely see sea levels rise 1.2 m this century, more than they have fluctuated naturally over 2000 years.

And temperatures will continue to rise. There is no doubt about this. The question is whether we can keep temperature increases from exceeding the +2ºC critical limit (as is generally agreed upon as the "point of no return" in climate"). With extreme regulation measures, we MIGHT be able to. If we keep heading on our current path, there is no chance.

(Click image to enlarge)

So, Rob, still thinking about taking that $10,000 bet?

A recent article in PNAS by Santer et al. (Proc. Natl. Acad. Sci. U.S.A. 106, 10.1073/pnas.0901736106, 2009) utilized 22 climate models to demonstrate that changes in water vapor (the most powerful natural greenhouse gas) distribution over the oceans is consistent with patterns caused specifically by anthropogenic forcing of climate. As water vapor is the fuel that powers hurricanes, they show a link between anthropogenic forcing and the recent increases in hurricane intensity. Of course, their real result is a demonstration that the Earth's recent warming patterns are human-caused. For a more detailed look at the intensification of hurricanes, check out http://www.toddalbert.com/comps/hurricanes/

Glaciers are responding to climate change in ways that we have expected for decades. The only difference is the speed. Around the world, glaciers are retreating at rates that are unprecedented, and previously deemed impossible. Thanks to some amazing time-lapse photography and an incredibly talented group of scientists, photographers, a large dose of ingenuity, and their intrepid crew, we can now witness the geologic process of glacier flow and retreat in some fantastic videos.

National Geographic photographer James Balog has teamed up with renown scientists Jason Box, Tad Pfeffer, Daniel Fagre, Alberto Behar and others to create the Extreme Ice Survey.

Visit the site now to watch glaciers in action!

When I first began studying global warming in 1995 I was extremely optimistic; we knew the science, the cause, the consequences, and the solutions, and it seemed as though a movement to stop the accelerating warming trend was building momentum. Then began a well-roganized campaign of misinformation spread through US media.

Interestingly, at the time I was completely unplugged from main-stream media. I didn't listen to the radio (only tapes). I didn't watch television (only movies). I didn't read newspapers (only peer-reviewed journals and texts). So I was completely out of the misinformation loop.

Instead, I was deeply focused on the science of climate change. I studied paleoclimatology (the long-term history of Earth's climate). I studied climatology. I studied meteorology. I studied glaciology. And I gained a deep enough understanding of the climate system to earn B.S., M.S., and Ph.D. degrees from 3 separate universities.

When I emerged, I realized that while I was racing ahead in my understanding of climate, the world, or at least a large portion of the US, seemed to be racing backward into a darker age of understanding. This has had several effects on me.

At first I lost my optimism. We were now a decade further along in our loading of greenhouse gasses into the atmosphere, but had made no progress on pursuing policies and implementing practices to slow or stop our emissions. Eventually I became excited -- since it seemed as though we've already passed some pretty important tipping points, perhaps I'll bear witness to some fantastic (albeit deadly) changes to the climate system. While disastrous, they will no doubt be fantastic.

Then I began my mission to educate as many as I can on the science of climate change. This is not a political issue any more than Newton's Laws of Motion or the Laws of Thermodynamics are political.

And the science of global warming is much older than most people realize...

The Science

It is easily demonstrated in a lab that when you pass visible light (sunlight) through a chamber filled with CO₂, the same amount of visible light comes out the other side (CO₂ is invisible). On the other hand, infrared radiation (heat from the Earth) is absorbed by this gas. So, the more CO₂ you put in your chamber, the less infrared comes out the other side.

The way the Earth maintains its temperature is by emitting the same amount of energy (in the infrared) that it absorbs from the Sun (visible light). Lucky for us, some of the Earth's heat is trapped by gasses like CO₂, which we call greenhouse gasses (GHGs). Otherwise, the Earth would be too cold for life as we know it.

Unfortunately, however, as we increase the amount of CO₂ (and other GHGs) in the air, more energy from the Earth is trapped and the Earth warms. We see evidence of this in samples of the atmosphere from Earth's past trapped in ice up to 1,000,000 years old. We can see from detailed climate records that as CO₂ concentrations in the atmosphere have risen and fallen, so have global temperatures.

Now, I would like to point out that global temperatures are not the best way to measure climate change. Climate refers to expected patterns of weather, and patterns are not always reflected by a simple average. For example, we can imagine two cities that both have an average temperature of 75ºF. One city fluctuates on a daily and annual basis between a high of 85ºF and a low of 65ºF (average is 75ºF). The other city fluctuates on a daily and annual basis between a high of 150ºF and a low of 0ºF (average is 75ºF). While both cities share a similar average, their climates are markedly different.

An analogy that I frequently use, too, is the difference between a simmering pot of water (212ºF or 100ºC) and water at a rolling boil (212ºF or 100ºC). Again, the temperature is the same, but the behavior of the fluid is quite different due to a small increase in energy.

A similar phenomenon is seen in our atmosphere. Less energy is leaving the system than is coming in. That excess energy is not all going into a change in temperature, however. Huge portions of that energy are being absorbed by the oceans (with great consequences) and Earth's ice, which is melting unusually fast.

History of the Science

While others start even earlier and give more details, I will only hit a few highlights.

1824: Jean-Baptiste Fourier first discusses the greenhouse effect (although I think that Al Gore put him up to it)

1861: John Tyndall published that CO₂ and H₂O are greenhouse gasses

1896: Svante Arrhenius proposed that burning fossil fuels will build-up CO₂ and lead to “desirable” warming (it was a cold year)

1938: G.S. Callendar argued that man-made global warming was already underway (was Al Gore born yet?)

1990: The 1980s are declared the warmest decade on record

1995: A general consensus is reached among scientists that man-made warming is underway

2000: The 1990s are declared the warmest decade in over 1,000 years

2003: William Ruddiman publishes that humans have been changing climate for 8,000 years

2007: Man-made warming is declared "unequivocal" by the larger science community

The Signs

I am often asked questions of the sort: "If global warming is underway, why was it so cold this January in Cleveland?"

First, one must realize that weather and climate are two different things. While the average temperature of the Earth is clearly on the rise, it not only fluctuates a bit from year to year, but also the warming is not evenly distributed in space and time. For example, winters and nights tend to be warming fastest (since the Earth cannot cool as readily). The polar regions and mountain regions are also warming especially fast.

But when you warm some places really fast, you tend to cool others. And this gets into more complex climatology, but I will try to explain it simply. Most of our weather patterns are controlled by big waves high up in the atmosphere, often referred to as jet streams. Poleward of these jet streams, the air tends to be much colder than on the tropical side. When a big wave forms in the jet, warm air is pushed towards the poles in one place, while colder air is thrust towards the tropics in the other. In this way, we've recently experienced some anomalously cold winters in Florida while Alaskans were getting rained on at Christmas time (is that how you make a baked Alaskan?).

These weather oddities are exactly what is expected. Variability will increase, although more of the extreme events will be on the warmer side than the colder.

In the Middle East, some in Saudi Arabia and Jordan witnessed their first snowfalls last winter.< center >

We are already seeing:

A rise in global mean temperature
A rise in global mean sea level
A drop in Northern hemisphere snow cover
Retreat of 95% of the world's glaciers outside of Antarctica (more than 2 TRILLION TONS of ice has melted just since 2003!)
Antarctic ice shelves are breaking-up
Antarctic Peninsula is quickly warming
Arctic sea ice melting faster than any predictions
Arctic regions are warming ten times faster than the global average
and much more

What will happen

Global average temperatures will continue to rise by 1–6ºC by 2100
Widespread hunger will strike as many agricultural areas dry out
Severe water shortages will strike, especially the 40% of the population that rely on glacier meltwater
Increases in both air-borne and insect-borne diseases
More extreme weather (e.g. droughts, flooding, heat-waves, and storms)
And the list goes on

Today is Michael Shermer's birthday, a famous science skeptic, and author of "Why People Believe Strange Things". One of his quotes really penetrates today: "Anecdotal thinking comes naturally; science requires training." I often find myself speaking to people who do not accept scientific facts as facts, nor do they understand that scientists, by nature, are skeptics. But, scientific laws do not waiver in the face of politics. Or, to paraphrase Gwynn Dyer, the second law of thermodynamics does not have a left and right side.

UPDATED! In my first radio broadcast, and my first scientific debate, I went head-to-head with Roy Spencer, a famous global warming denier on the radio show Political Animals. You can listen to the show here. I debate Roy Spencer for about 30 minutes. Then I am on for another hour with the hosts and callers.

Update: You don't need to skip the first 25 minutes -- I cut it to jump right in to my part.