As the battle over the Keystone XL pipeline has worn on -- and it's now well over two years old -- it's illuminated the Obama presidency like no other issue. It offers the president not just a choice of policies, but a choice of friends, worldviews, styles. It's become an X-ray for a flagging presidency. The stakes are sky-high, and not just for Obama. I'm writing these words from Pittsburgh, amid 7,000 enthusiastic and committed young people gathering to fight global warming, and my guess is that his choice will do much to determine how they see politics in this country.

Let us stipulate at the start that whether or not to build the pipeline is a decision with profound physical consequences. If he approves its construction, far more of the dirtiest oil on Earth will flow out of the tar sands of Alberta, Canada, and reach the U.S. Gulf Coast. Not just right away or for a brief period, but far into the future, since the Keystone XL guarantees a steady flow of profits to oil barons who have their hearts set on tripling production in the far north.

The history of oil spills and accidents offers a virtual guarantee that some of that oil will surely make its way into the fields and aquifers of the Great Plains as those tar sands flow south. The greater and more daunting assurance is this, however: everything that reaches the refineries on the Gulf Coast will, sooner or later, spill into the atmosphere in the form of carbon, driving climate change to new heights.

These days, however, as no one will be surprised to hear, brainless things happen in Washington more often than not, and there's the usual parade of the usual suspects demanding that Keystone get built. In mid-October, a coalition that included Exxon, Chevron, ConocoPhillips, and Royal Dutch Shell, not to mention the U.S. Chamber of Commerce, the National Association of Manufacturers, and the Business Roundtable, sent Obama a letter demanding that he approve Keystone in order to "maintain investor confidence," a phrase almost guaranteed to accompany bad ideas. A report last week showed that the Koch brothers stood to earn as much as $100 billion in profits if the pipeline gets built (which would come in handy in helping fund their endless assault on unions, poor people, and democracy).

But don't think it's just Republican bigwigs and oil execs rushing to lend the pipeline a hand. Transcanada, the pipeline's prospective builder, is at work as well, and Obama's former communications director Anita Dunn is now on the Transcanada dime, producing TV ads in support of the pipeline. It's a classic example of the kind of influence peddling that knows no partisan bounds. As the activists at Credo put it: "It's a betrayal of the commitments that so many of us worked so hard for, and that Dunn herself played a huge role in shaping as top strategist on the 2008 campaign and communications director in the White House."

Credo's Elijah Zarlin, who worked with Dunn back in 2008, wrote that attack on her. He was the guy who wrote all those emails that got so many of us coughing up money and volunteering time during Obama's first run for the presidency, and he perfectly exemplifies those of us on the other side of this divide -- the ones who actually believed Dunn in 2008, the ones who thought Obama was going to try to be a different kind of president.

On energy there's been precious little sign of that. Yes, the Environmental Protection Agency has put in place some new power plant regulations, and cars are getting better mileage. But the president has also boasted again and again about his "all of the above" energy policy for "increasing domestic oil production and reducing our dependence on foreign oil." It has, in fact, worked so well that the United States will overtake Russia this year as the biggest combined oil and natural gas producer on the planet and is expected to pass Saudi Arabia as the number one oil producer by 2017.

His administration has okayed oil drilling in the dangerous waters of the Arctic and has emerged as the biggest backer of fracking. Even though he boasts about marginal U.S. cuts in carbon emissions, his green light to fracking means that he's probably given more of a boost to releases of methane -- another dangerous greenhouse gas -- than any man in history. And it's not just the environment. At this point, given what we know about everything from drone warfare to NSA surveillance, the dream of a progressive Obama has, like so many dreams, faded away.

The president has a handy excuse, of course: a truly terrible Congress. And too often -- with the noble exception of those who have been fighting for gay rights and immigration reform -- he's had little challenge from progressives. But in the case of Keystone, neither of those caveats apply: he gets to make the decision all by himself with no need to ask John Boehner for a thing, and people across the country have made a sustained din about it. Americans have sent record numbers of emails to senators and a record number of comments to the State Department officials who oversee a "review" of the pipeline's environmental feasibility; more have gone to jail over this issue than any in decades. Yet month after month, there's no presidential decision.

There are days, in fact, when it's hard to muster much fire for the fight (though whenever I find my enthusiasm flagging, I think of the indigenous communities that have to live amid the Mordor that is now northern Alberta). The president, after all, has already allowed the construction of the southern half of the Keystone pipeline, letting Transcanada take land across Texas and Oklahoma for its project, and setting up the beleaguered communities of Port Arthur, Texas, for yet more fumes from refineries.

Stopping the northern half of that pipeline from being built certainly won't halt global warming by itself. It will, however, slow the expansion of the extraction of tar sands, though the Koch brothers et al. are busy trying to find other pipeline routes and rail lines that would get the dirtiest of dirty energy out of Canada and into the U.S. via destinations from Michigan to Maine. These pipelines and rail corridors will need to be fought as well -- indeed the fights are underway, though sometimes obscured by the focus on Keystone. And there are equally crucial battles over coal and gas from the Appalachians to the Pacific coast. You can argue that the president's people have successfully diverted attention from their other environmental sins by keeping this argument alive long past the moment at which it should have been settled and a decision should have been made.

At this point, in fact, only the thought of those 900,000 extra barrels a day of especially nasty oil coming out of the ground and, via that pipeline, into refineries still makes the fight worthwhile. Oh, and the possibility that, in deciding to block Keystone, the president would finally signal a shift in policy that matters, finally acknowledge that we have to keep most of the carbon that's still in the ground in that ground if we want our children and grandchildren to live on a planet worth inhabiting.

If the president were to become the first world leader to block a big energy project on the grounds of its effects on climate, it might help dramatically reset the international negotiations that he allowed to go aground at Copenhagen in 2009 -- the biggest foreign policy failure of his first term.

But that cascade of "ifs" depends on Obama showing that he can actually stand up to the oil industry. To an increasingly disillusioned environmental movement, Keystone looks like a last chance.
(c) 2013 Bill McKibben is Schumann Distinguished Scholar at Middlebury College, co=founder of 350.org. His most recent book is Eaarth: Making a Life on a Tough New Planet.

IS ISRAEL an apartheid state? This question is not going away. It raises its head every few months.

The term "apartheid" is often used purely for propaganda purposes. Apartheid, like racism and fascism, is a rhetorical term one uses to denigrate one's opponent.

But apartheid is also a term with a precise content. It applies to a specific regime. Equating another regime to it may be accurate, partly correct or just wrong. So, necessarily, will be the conclusions drawn from the comparison.

RECENTLY I had the opportunity to discuss this subject with an expert, who had lived in South Africa throughout the apartheid era. I learned a lot from this.

Is Israel an apartheid state? Well, first one must settle the question: which Israel? Israel proper, within the Green Line, or the Israeli occupation regime in the occupied Palestinian territories, or both together?

Let's come back to that later.

THE DIFFERENCES between the two cases are obvious.

First, the SA regime was based, as with their Nazi mentors, on the theory of racial superiority. Racism was its official creed. The Zionist ideology of Israel is not racist, in this sense, but rather based on a mixture of nationalism and religion, though the early Zionists were mostly atheists.

The founders of Zionism always rejected accusations of racism as absurd. It's the anti-Semites who are racist. Zionists were liberal, socialist, progressive. (As far as I know, only one Zionist leader had openly endorsed racism: Arthur Ruppin, the German Jew who was the father of the Zionist settlements in the early 20th century.)

Then there are the numbers. In SA there was a huge black majority. Whites were about a fifth of the population.

In Israel proper, the Arab citizens constitute a minority of about 20%. In the total territory under Israeli rule between the Mediterranean Sea and the Jordan River, the numbers of Jews and Arabs are roughly equal. The Arabs may by now constitute a small majority - precise numbers are hard to come by. This Arab majority is bound to grow slowly larger as time passes.

Furthermore, the white economy in SA was totally dependent on black labor. At the beginning of the Israeli occupation of the West Bank and the Gaza strip in 1967, the Zionist insistence on "Jewish Labor" came to an end and cheap Arab labor from the "territories" flooded Israel. However, with the beginning of the first intifada this development was stopped with surprising speed. Large numbers of foreign workers were imported: Eastern Europeans and Chinese for the building trade, Thais for agriculture, Philippinos for personal care, etc.

It is now one of the main jobs of the Israeli army to prevent Palestinians from illegally crossing the de facto border" into Israel to seek work.

This is a fundamental difference between the two cases, one that has a profound impact on the possible solutions.

Sadly, in the West Bank, the Palestinians are widely employed in the building of the settlements and work in the enterprises there, which my friends and I have called to boycott. The economic misery of the population drives them to this perverse situation.

In Israel proper, Arab citizens complain about discrimination, which limits their employment in Jewish enterprises and government offices. The authorities regularly promise to do something about this kind of discrimination.

On the whole, the situation of the Arab minority inside Israel proper is much like that of many national minorities in Europe and elsewhere. They enjoy equality under the law, vote for parliament, are represented by very lively parties of their own, but in practice suffer discrimination in many areas. To call this apartheid would be grossly misleading.

I ALWAYS thought that one of the major differences was that the Israeli regime in the occupied territories expropriates Palestinian lands for Jewish settlements. This includes private property and so-called "government lands".

In Ottoman times, the land reserves of the towns and villages were registered in the name of the Sultan. Under the British, these lands became government property, and they remained so under the Jordanian regime. When Israel occupied the West Bank in 1967, these lands were taken over by the occupation regime and turned over to the settlers, depriving the Palestinian towns and villages of the land reserves they need for natural increase.

By the way, after the 1948 war, huge stretches of Arab land in Israel were expropriated and a wide array of laws enacted for this purpose - not only the "absentee" property of the refugees, but also lands of Arabs who were declared "present absentees"' - an absurd term meaning people who had not left Israel during the war but had left their villages. And the "government lands" in the part of Palestine that had become Israel also served to settle the masses of new Jewish immigrants who streamed into the country.

I always thought that in this respect we were worse than SA. Not so, said my friend, the apartheid government did exactly the same, deporting Blacks to certain areas and grabbing their land for Whites Only.

I ALWAYS thought that in SA all the Whites were engaged in the fight against all the Blacks. However, it appears that both sides were profoundly divided.

On the white side, there were the Afrikaners, the descendents of Dutch settlers, speaking a Dutch dialect called Afrikaans, and the British who spoke English. These were two communities of roughly equal size who disliked each other intensely. The British despised the unsophisticated Afrikaners, the Afrikaners hated the effete British. Indeed, the apartheid party called itself "nationalist" mainly because it considered itself a nation born in the country, while the British were attached to their homeland. (I am told that the Afrikaners called the British "salty penis", because they stood with one foot in SA and with the other in Britain, so that their sexual organ dipped into the ocean.)

The black population was also divided into many communities and tribes who did not like each other, making it difficult for them to unite for the liberation struggle.

THE SITUATION in the West Bank is in many ways similar to the apartheid regime.

Since Oslo, the West Bank is divided into areas A, B and C, in which Israeli rule is exercised in different ways. In SA, there were many different Bantustans ("homelands") with different regimes. Some were officially fully autonomous, others were partly so. All were enclaves surrounded by white territories.

In certain respects, the situation in SA was at least officially better than in the West Bank. Under SA law, the Blacks were at least officially "separate but equal". The general law applied to all. This is not the case in our occupied territories, where the local population is subject to military law, which is quite arbitrary, while their settler neighbors are subject to Israeli civil law.

ONE CONTENTIOUS question: how far - if at all - did the international boycott contribute to the downfall of the apartheid regime?

When I asked Archbishop Desmond Tutu, he answered that the effect was mainly moral. It raised the morale of the black community. My new friend said the same - but applied it to the Whites. Their morale was undermined.

How much did this contribute to the victory? My friend estimated: about 30%.

The economic effect was minor. The psychological effect was far more important. The Whites considered themselves the vanguard of the West in the fight against communism. The ungratefulness of the West stunned them. (They would have wholeheartedly subscribed to the promise of Theodor Herzl, the founder of the Zionist movement, that the future Jewish state would be the vanguard of Europe and a wall against Asiatic - viz. Arab - barbarism.)

It was no accident that apartheid broke down a few years after the collapse of the Soviet empire. The US lost interest. Can this happen in our relations with the US, too?

(By the way, young South African blacks who were sent by the African National Congress to the Soviet Union to study were shocked by the racism they met there. "They are worse than our Whites," they commented.)

THE AREA where the boycott hit the apartheid people the most was sports. Cricket is a national obsession in SA. When they could no longer take part in international competitions, they felt the blow. Their self-confidence was broken.

Their international isolation forced them to think more deeply about the morality of apartheid. There was more and more self-questioning. In the final elections after the agreement, many Whites, including many Afrikaners, voted for the end of apartheid.

Will a boycott of Israel have the same effect? I doubt it. Jews are used to being isolated. "The whole world against us" is, for them, a natural situation. Indeed, I sometimes have the feeling that many Jews feel uncomfortable when the situation is different.

One huge difference between the two cases is that all South Africans - black, white, "coloured" or Indian - wanted one state. There were no takers for partition. (David Ben-Gurion, a great advocate of Palestine-style partition, once proposed concentrating all the Whites in SA in the Cape region and establishing there an Israel-style white state. No one was interested. A similar proposal by Ben-Gurion for Algeria met the same fate.)

In our case, a large majority on each side wants to live in a state of their own. The idea of a unified country, in which Hebrew-speaking Jewish Israelis and Arabic-speaking Palestinians will live side-by-side as equals, serving in the same army and paying the same taxes does not appeal to them at all.

APARTHEID WAS brought down by the Blacks themselves. No crypto-colonialist condescension can obscure this fact.

The mass strikes of African workers, on whom the white economy depended, made the position of the ruling Whites impossible. The mass uprising of the Blacks, who displayed immense physical courage, was decisive. In the end, the Blacks liberated themselves.

Thirty years ago, on October 25, 1983, the United States sent 6,000 elite troops to overwhelm the Caribbean nation of Grenada, an island of less than 100,000 inhabitants that had been governed by the revolutionary New Jewel Movement since 1979. Although the announced pretext for the invasion was a nonexistent threat to American medical students on the island, Operation Urgent Fury had been rehearsed two years earlier, in a 1981 war game against the island nation of "Amber and the Amberdines," a fictional stand-in for Grenada and the Grenadines.

Washington's larger, strategic rationale for marshalling overwhelming force against an unoffending, 133 square mile pinpoint of a country off the coast of Venezuela, whose biggest export was nutmeg and whose security forces probably numbered no more than 1,200, was that Cuba and/or the Soviets were poised to turn Grenada into a military and/or "terrorist" base. A new and desperately needed airport was under construction, paid for by Britain, the former colonial master, Cuba, Libya, and Algeria, with Cuba supplying the bulk of construction workers. The runway, just south of the gorgeous arc of Grand Anse beach and the tiny capital city, St. George's, would finally allow tourists to enter Grenada by commercial jet, replacing the perilous propeller drop into a narrow strip between a mountain and the ocean on the island's northern shore.

Objectively, the old airport was the most dangerous thing about Grenada, where the mostly white medical school students constituted the largest foreign presence and life was laid-back, even by Caribbean standards. Grenada's real threat was ideological. Its youthful, Marxist-oriented government, Washington feared, might serve as a model for others in the hemisphere - "another Cuba," or Nicaragua, whose Sandinista revolutionaries had also come to power in 1979.

Although conquest of Grenada presented no real military challenge for the superpower, the island's very minuteness made U.S. invasion politically problematical. The Reagan administration found itself oscillating between characterizing the aggression as a rescue mission to save American students, to an urgent strategic counter-move in the global fight against communism ("US Delegate in UN Calls Invasion an Act of Defense," read the October 28 New York Times headline), or some combination of the two, as in the Washington Post's October 26 headline, "Strategic Airport, Hostage Fear Led to Move."

Operation Urgent Fury was most urgently opportunistic. A long-simmering political crisis within the New Jewel Movement led, disastrously, to the house arrest of popular Prime Minister Maurice Bishop by other members of the ruling party, on October 12. Bishop and a crowd of supporters later marched on army headquarters, at Fort Rupert, on October 19, in a bid to take back power. Many were killed in the fighting, Bishop and other officials were executed, and the country was placed under marshal law. U.S. forces, which appeared to have been made ready early in the Grenadian political crisis, hit the beaches and parachuted onto the unfinished airport runway on October 25.

The Grenadian armed forces put up what resistance they could, given the overwhelming firepower and numbers of the enemy and the fratricidal trauma the Grenadian nation had just undergone. However, the superpower could not allow itself to be seen as an elephant stomping on a flea. Therefore, all dead bodies recovered on the island were initially designated as "Cuban," except for the 21 patients and staff killed in the U.S. bombing of the mental hospital, at St. George's, in the first day of the invasion. The official line, dutifully parroted by the press, was that only Cuban soldiers - 1,100 of them - had resisted the American assault. In fact, Cuban nationals on the island numbered only about 700, most of them unarmed, pot-bellied construction workers. Cuban military personnel defended only their embassy. Twenty-four Cubans died in the early days of the invasion, along with probably several hundred Grenadian military. But, for weeks, the Americans claimed to be chasing an elusive force of Cuban super-soldiers around island. The New York Times relayed a U.S. military estimate that 500 Cubans had "fled into the hills." These phantom Cubans live on in the 1986 Clint Eastwood movie Heartbreak Ridge, in which Eastwood and his platoon do battle with Castro's men in the hills of the island. (For Fidel Castro's remarks at the funeral of Cuba's real-life casualties in Grenada, click HERE.)

By November 13, three weeks into the invasion, the New York Times was still reporting that Grenadians have been passive in the invasion of their own country. "Grenadians Toll Put by U.S. at 21: Americans Appear to Believe that All Combatants Killed in Battle Were Cubans." The bombing of the mental hospital, where the only acknowledged Grenadian fatalities occurred, was an "accident," said the Reagan administration. Indeed, the U.S. action was not an "invasion" at all, but an "intervention." The New York Times loyally purged "invasion" from its vocabulary until the last phantom Cuban disappeared from the Grenadian hills.

The Grenada invasion was, in a sense, simply a continuation of U.S. "gunboat diplomacy" in the Western Hemisphere, as was practiced as late as 1965, in the invasion-intervention of the Dominican Republic, which was also undertaken under the hybrid rationales of "not another Cuba" and "rescue of American nationals." However, Grenada may have been the first U.S. occupation in which members of the native government and armed forces that had evaded death or capture were immediately dubbed "fugitives" - outlaws in their own land, where they had been the lawful and recognized authority, only days before.

In December 2012, a pink-haired complex systems researcher named Brad Werner made his way through the throng of 24,000 earth and space scientists at the Fall Meeting of the American Geophysical Union, held annually in San Francisco. This year's conference had some big-name participants, from Ed Stone of Nasa's Voyager project, explaining a new milestone on the path to interstellar space, to the film-maker James Cameron, discussing his adventures in deep-sea submersibles.

But it was Werner's own session that was attracting much of the buzz. It was titled "Is Earth F**ked?" (full title: "Is Earth F**ked? Dynamical Futility of Global Environmental Management and Possibilities for Sustainability via Direct Action Activism").

Standing at the front of the conference room, the geophysicist from the University of California, San Diego walked the crowd through the advanced computer model he was using to answer that question. He talked about system boundaries, perturbations, dissipation, attractors, bifurcations and a whole bunch of other stuff largely incomprehensible to those of us uninitiated in complex systems theory. But the bottom line was clear enough: global capitalism has made the depletion of resources so rapid, convenient and barrier-free that "earth-human systems" are becoming dangerously unstable in response. When pressed by a journalist for a clear answer on the "are we f**ked" question, Werner set the jargon aside and replied, "More or less."

There was one dynamic in the model, however, that offered some hope. Werner termed it "resistance" - movements of "people or groups of people" who "adopt a certain set of dynamics that does not fit within the capitalist culture." According to the abstract for his presentation, this includes "environmental direct action, resistance taken from outside the dominant culture, as in protests, blockades and sabotage by indigenous peoples, workers, anarchists and other activist groups."

Serious scientific gatherings don't usually feature calls for mass political resistance, much less direct action and sabotage. But then again, Werner wasn't exactly calling for those things. He was merely observing that mass uprisings of people - along the lines of the abolition movement, the civil rights movement or Occupy Wall Street - represent the likeliest source of "friction" to slow down an economic machine that is careening out of control. We know that past social movements have "had tremendous influence on ... how the dominant culture evolved", he pointed out. So it stands to reason that, "if we're thinking about the future of the earth, and the future of our coupling to the environment, we have to include resistance as part of that dynamics." And that, Werner argued, is not a matter of opinion, but "really a geophysics problem."

Plenty of scientists have been moved by their research findings to take action in the streets. Physicists, astronomers, medical doctors and biologists have been at the forefront of movements against nuclear weapons, nuclear power, war, chemical contamination and creationism. And in November 2012, Nature published a commentary by the financier and environmental philanthropist Jeremy Grantham urging scientists to join this tradition and "be arrested if necessary", because climate change "is not only the crisis of your lives - it is also the crisis of our species' existence."

Some scientists need no convincing. The godfather of modern climate science, James Hansen, is a formidable activist, having been arrested some half-dozen times for resisting mountain-top removal coal mining and tar sands pipelines (he even left his job at Nasa this year in part to have more time for campaigning). Two years ago, when I was arrested outside the White House at a mass action against the Keystone XL tar sands pipeline, one of the 166 people in cuffs that day was a glaciologist named Jason Box, a world-renowned expert on Greenland's melting ice sheet.

"I couldn't maintain my self-respect if I didn't go," Box said at the time, adding that "just voting doesn't seem to be enough in this case. I need to be a citizen also."

This is laudable, but what Werner is doing with his modelling is different. He isn't saying that his research drove him to take action to stop a particular policy; he is saying that his research shows that our entire economic paradigm is a threat to ecological stability. And indeed that challenging this economic paradigm - through mass-movement counter-pressure - is humanity's best shot at avoiding catastrophe.

That's heavy stuff. But he's not alone. Werner is part of a small but increasingly influential group of scientists whose research into the destabilisation of natural systems - particularly the climate system - is leading them to similarly transformative, even revolutionary, conclusions. And for any closet revolutionary who has ever dreamed of overthrowing the present economic order in favour of one a little less likely to cause Italian pensioners to hang themselves in their homes, this work should be of particular interest. Because it makes the ditching of that cruel system in favour of something new (and perhaps, with lots of work, better) no longer a matter of mere ideological preference but rather one of species-wide existential necessity.

Leading the pack of these new scientific revolutionaries is one of Britain's top climate experts, Kevin Anderson, the deputy director of the Tyndall Centre for Climate Change Research, which has quickly established itself as one of the UK's premier climate research institutions. Addressing everyone from the Department for International Development to Manchester City Council, Anderson has spent more than a decade patiently translating the implications of the latest climate science to politicians, economists and campaigners. In clear and understandable language, he lays out a rigorous road map for emissions reduction, one that provides a decent shot at keeping global temperature rise below 2° Celsius, a target that most governments have determined would stave off catastrophe.

But in recent years Anderson's papers and slide shows have become more alarming. Under titles such as "Climate Change: Going Beyond Dangerous ... Brutal Numbers and Tenuous Hope", he points out that the chances of staying within anything like safe temperature levels are diminishing fast.

With his colleague Alice Bows, a climate mitigation expert at the Tyndall Centre, Anderson points out that we have lost so much time to political stalling and weak climate policies - all while global consumption (and emissions) ballooned - that we are now facing cuts so drastic that they challenge the fundamental logic of prioritising GDP growth above all else.

Anderson and Bows inform us that the often-cited long-term mitigation target - an 80 per cent emissions cut below 1990 levels by 2050 - has been selected purely for reasons of political expediency and has "no scientific basis". That's because climate impacts come not just from what we emit today and tomorrow, but from the cumulative emissions that build up in the atmosphere over time. And they warn that by focusing on targets three and a half decades into the future - rather than on what we can do to cut carbon sharply and immediately - there is a serious risk that we will allow our emissions to continue to soar for years to come, thereby blowing through far too much of our 2 degree "carbon budget" and putting ourselves in an impossible position later in the century.

Which is why Anderson and Bows argue that, if the governments of developed countries are serious about hitting the agreedupon international target of keeping warming below 2 degrees Celsius, and if reductions are to respect any kind of equity principle (basically that the countries that have been spewing carbon for the better part of two centuries need to cut before the countries where more than a billion people still don't have electricity), then the reductions need to be a lot deeper, and they need to come a lot sooner.

To have even a 50/50 chance of hitting the 2 degree target (which, they and many others warn, already involves facing an array of hugely damaging climate impacts), the industrialised countries need to start cutting their greenhouse-gas emissions by something like 10 per cent a year - and they need to start right now. But Anderson and Bows go further, pointing out that this target cannot be met with the array of modest carbonpricing or green-tech solutions usually advocated by big green groups. These measures will certainly help, to be sure, but they are simply not enough: a 10 per cent drop in emissions, year after year, is virtually unprecedented since we started powering our economies with coal. In fact, cuts above 1 per cent per year "have historically been associated only with economic recession or upheaval", as the economist Nicholas Stern put it in his 2006 report for the British government.

Even after the Soviet Union collapsed, reductions of this duration and depth did not happen (the former Soviet countries experienced average annual reductions of roughly 5 per cent over a period of ten years). They did not happen after Wall Street crashed in 2008 (wealthy countries experienced about a 7 per cent drop between 2008 and 2009, but their CO2 emissions rebounded with gusto in 2010 and emissions in China and India had continued to rise). Only in the immediate aftermath of the great market crash of 1929 did the United States, for instance, see emissions drop for several consecutive years by more than 10 per cent annually, according to historical data from the Carbon Dioxide Information Analysis Centre. But that was the worst economic crisis of modern times.

If we are to avoid that kind of carnage while meeting our science-based emissions targets, carbon reduction must be managed carefully through what Anderson and Bows describe as "radical and immediate de-growth strategies in the US, EU and other wealthy nations". Which is fine, except that we happen to have an economic system that fetishises GDP growth above all else, regardless of the human or ecological consequences, and in which the neoliberal political class has utterly abdicated its responsibility to manage anything (since the market is the invisible genius to which everything must be entrusted).

So what Anderson and Bows are really saying is that there is still time to avoid catastrophic warming, but not within the rules of capitalism as they are currently constructed. Which may be the best argument we have ever had for changing those rules.

In a 2012 essay that appeared in the influential scientific journal Nature Climate Change, Anderson and Bows laid down something of a gauntlet, accusing many of their fellow scientists of failing to come clean about the kind of changes that climate change demands of humanity. On this it is worth quoting the pair at length:

... in developing emission scenarios scientists repeatedly and severely underplay the implications of their analyses. When it comes to avoiding a 2 degree C rise, "impossible" is translated into "difficult but doable", whereas "urgent and radical" emerge as "challenging" - all to appease the god of economics (or, more precisely, finance). For example, to avoid exceeding the maximum rate of emission reduction dictated by economists, "impossibly" early peaks in emissions are assumed, together with naive notions about "big" engineering and the deployment rates of low-carbon infrastructure. More disturbingly, as emissions budgets dwindle, so geoengineering is increasingly proposed to ensure that the diktat of economists remains unquestioned.

In other words, in order to appear reasonable within neoliberal economic circles, scientists have been dramatically soft-peddling the implications of their research. By August 2013, Anderson was willing to be even more blunt, writing that the boat had sailed on gradual change. "Perhaps at the time of the 1992 Earth Summit, or even at the turn of the millennium, 2 degrees C levels of mitigation could have been achieved through significant evolutionary changes within the political and economic hegemony. But climate change is a cumulative issue! Now, in 2013, we in high-emitting (post-)industrial nations face a very different prospect. Our ongoing and collective carbon profligacy has squandered any opportunity for the 'evolutionary change' afforded by our earlier (and larger) 2 degrees C carbon budget. Today, after two decades of bluff and lies, the remaining 2°C budget demands revolutionary change to the political and economic hegemony" (his emphasis).

We probably shouldn't be surprised that some climate scientists are a little spooked by the radical implications of even their own research. Most of them were just quietly doing their work measuring ice cores, running global climate models and studying ocean acidification, only to discover, as the Australian climate expert and author Clive Hamilton puts it, that they "were unwittingly destabilising the political and social order".

But there are many people who are well aware of the revolutionary nature of climate science. It's why some of the governments that decided to chuck their climate commitments in favour of digging up more carbon have had to find ever more thuggish ways to silence and intimidate their nations' scientists. In Britain, this strategy is becoming more overt, with Ian Boyd, the chief scientific adviser at the Department for Environment, Food and Rural Affairs, writing recently that scientists should avoid "suggesting that policies are either right or wrong" and should express their views "by working with embedded advisers (such as myself), and by being the voice of reason, rather than dissent, in the public arena".

If you want to know where this leads, check out what's happening in Canada, where I live. The Conservative government of Stephen Harper has done such an effective job of gagging scientists and shutting down critical research projects that, in July 2012, a couple thousand scientists and supporters held a mock-funeral on Parliament Hill in Ottawa, mourning "the death of evidence". Their placards said, "No Science, No Evidence, No Truth".

But the truth is getting out anyway. The fact that the business-as-usual pursuit of profits and growth is destabilising life on earth is no longer something we need to read about in scientific journals. The early signs are unfolding before our eyes. And increasing numbers of us are responding accordingly: blockading fracking activity in Balcombe; interfering with Arctic drilling preparations in Russian waters (at tremendous personal cost); taking tar sands operators to court for violating indigenous sovereignty; and countless other acts of resistance large and small. In Brad Werner's computer model, this is the "friction" needed to slow down the forces of destabilisation; the great climate campaigner Bill McKibben calls it the "antibodies" rising up to fight the planet's "spiking fever".