The mathematics of the climate crisis is easy to understand once you have the key numbers. And those numbers lead to some clear and compelling conclusions.

Following the well-known laws of physics, carbon dioxide traps and preserves heat in the atmosphere. Without it, we’d be frozen space-bunnies without a gram of civilization to rub between us.

At 280 parts of CO2 per million, it’s a bit hot in the tropics, a bit cold in the Arctic, but overall, as Goldilocks might say, it’s just right. Every spring, when the forests in Earth’s north breathe in CO2, the atmospheric CO2 dips. Every fall, when they release their leaves, it rises. As Joni Mitchell might put it:

The carbon cycles go round and round,

The CO2 goes up and down,

We’re captive on a carousel of time.

The Immense Power of Ancient Fossil Fuels

But starting in the 1760s, when we began to burn the immense power of ancient fossil fuels that date from long before the age of the dinosaurs, the carbon carousel began to get a bit crazy. The yearly variation remains the same, but every year the CO2 rises because of all the ancient carbon we are adding, every molecule of which traps additional heat.

We can’t return, we can only look behind

From where we came,

And go up and up and up

In the climate game.

Before the industrial age, Earth’s atmosphere contained 280 parts per million of carbon dioxide (CO2). Since then we have pushed the CO2 up to 400 parts per million. So what’s the limit? How much more can we add before the temperature rises beyond the climate danger threshold?[1]

In a major paper published in December 2013 the top NASA climate scientist James Hansen and his team of researchers concluded that 2°C is “far into the dangerous range,” and if the current rate of emissions continues much longer, “it will become exceedingly difficult to keep the warming below a target smaller than 2°C.” [2]

In reality, we have already passed various dangerous tipping points, and 2°C is the boundary between ‘dangerous’ and ‘very dangerous.’ Hansen has warned us that adopting a goal of limiting CO2 emissions to 450 parts per million and hoping to limit the warming to 2°C is a “prescription for disaster,” due to additional tipping points that will be crossed on the way to 2°C. [3]

In a parallel universe of some kind we would have begun far earlier, and we would not be where we are today. Here is where we are, however. So is there a way to minimize the danger?


In 2009, a team of climate scientists from the Potsdam Institute of Climate Impact Research in Germany led by Malte Meinshausen ran a complex set of climate calculations, which they published in Nature under the title Greenhouse-gas emissions targets for limiting global warming to 2°C. [4]

Before I lay out their numbers, let me pose this question: If the pilot of a plane that you and your family were about to board told you there was a 25% chance that the plane would crash, would you still board?

Most of us don’t need long to answer that one, yet those are the stakes we are playing with, for both our civilization and the integrity of nature.


In their paper, Meinshausen’s team calculated that over the period 2000 to 2050 releasing an additional 1,000 Gt of carbon dioxide will bring a 25% chance that we’ll crash through the 2°C barrier. That’s like Russian Roulette, but with (almost) two bullets in the chambers, not one.

Note to brain: One megatonne (Mt) is a million tonnes. One gigatonne (Gt) is a billion tonnes. 1,000 Gt is a trillion tonnes.

If you fancy yourself as a scarily bad-assed extreme climate danger freak, increasing the total to 1,440 Gt lifts the chance of failure to 50%. That’s Russian Roulette with three bullets, three empty chambers.

These numbers are for the period 2000 to 2050, and now it’s 2015. Since 2000, globally, we have released a further 507 Gt of CO2, and the rate of emissions is going up, not down, in spite of the encouraging acceleration of renewable energy. In 1975 the world was releasing 17 Gt of CO2 a year. Today, it’s releasing 40 Gt per year.

These numbers are for carbon pollution only. The other greenhouse gases also need to be reduced, but I’ll postpone discussion of them to Part 2, which will be published in a couple of weeks.


Subtract the 507 Gt we have already released since 2000 from 1,000 Gt and we’re left with 493 Gt of CO2 that can be emitted globally while still keeping a 25% chance of staying below a 2 degrees increase. Divide that by 40 Gt a year, our current annual rate emissions, and in twelve years it’s all gone. If we’re willing to risk a “50% chance of failure” the budget is larger, but it’s still exhausted by 2037.

The corporations and countries that own the rights to extract and sell the fossil fuels, meanwhile, are planning to burn six times more than the 25% failure scenario, all with a straight face designed for their investors.

In January 2015, Christophe McGlade and Paul Ekins published a paper in Nature which gained a lot of media attention titled The geographical distribution of fossil fuels unused when limiting global warming to 2°C. They too concluded that most fossil fuels will need to remain in the ground, including 82% of the world’s coal, 88% of the unconventional fracked gas, and virtually all of Canada’s oil sands. [5]


If the 2015 global carbon budget in the “25% chance of failure” scenario is 493 Gt, how much of that share is Canada’s?

If the global budget is shared by population, Canada’s share is 0.5%, or 2.4 Gt, or 2,400 million tonnes.[6] Since Canada’s annual CO2 emissions are 500 megatonnes, at the current rate that budget would be exhausted in five years. To remain within the budget we would need to reduce our emissions by 20% this year and by the same amount for each of the next five years. I’ve not met anyone, however far out, who believes this to be possible.

If the budget is shared by current emissions, Canada’s 500 Mt is 1.25% of the global annual 40,000 Mt a year. As a share of the global budget that comes to just over 6Gt or 6,000 Mt, and if we continue our current very low speed of reduction it will be exhausted by 2028.

So here’s the thing. We have a federal election coming up, and many people see it as critical that the climate crisis become an election issue. The only policy being discussed much, however, is putting a price on carbon, whether through a straight carbon tax (as in British Columbia and several countries) a system of cap and trade, which the NDP (“a revenue-generating carbon market”) supports, or a carbon fee and dividend, which The Green Party favours.

Without the discipline of the global carbon budget, however, it’s all rather vague. It’s like setting out to get somewhere without a map, and without knowing where you’re going. BC’s carbon tax reduced per capita consumption of fuel by 19% over four years and greenhouse gases from fuel by 9% without any economic adversity, so putting a price on carbon is clearly good policy, but it’s not sufficient. [7]

The carbon numbers bring discipline to climate policy-making. They tell us in no uncertain terms that if we adopt the ‘share of current emissions’ budget, Canada has just six gigatonnes of future emissions to play with, and then it’s bedtime: zero.

When you compare the current policies, with their rather vague future goals and their rather vague promises of carbon-pricing, it’s the difference between a parent saying “Please be nice and go to bed sometime soon,” and saying “If you are not in bed within twenty minutes you’ll be cleaning the toilet every day for next 30 days,” and meaning it.


With Canada’s carbon budget in hand, an immediately obvious question follows: “What is the optimum rate of reduction that will allow Canada to achieve a smooth transition to zero, while remaining within the allotted budget?”

Canada’s emissions reduction has averaged 7 Mt a year since emissions peaked in 2005, falling to 3.5 Mt a year over the last five years. If we continue to reduce by only 5 Mt a year we will burn through the entire budget by 2028 while only achieving a 13% reduction in annual emissions, compared to 2015.

At this rate, it will take Canada a hundred years to get to zero, while using use four times the allotted budget. This snail-like pace might suit Canada’s fossil fuel industry, but if the rest of the world acts in the same slow way it will bring disaster to all of us.

So if 5 Mt a year is not enough, what’s the right number? The table shows that 10 Mt a year is not enough; 15 Mt a year is not enough; and 20 Mt a year blows through the budget by 2041 without reaching zero, and they all require starting this year, which is clearly not happening. Only reducing by 25 Mt a year or more is effective, achieving a 100% transition to renewable energy while remaining within the budget.

When it comes to the UN climate conference in Paris in December 2015, reducing by 25 Mt a year would allow Canada to table a goal of a 25% reduction in current emissions by 2020 (27% below 1990), assuming a similar planned reduction of the other greenhouse gases. This compares to the European Union’s commitment of 20% below 1990. Zero by 2040 is close to Denmark’s goal of zero by 2050. [8]

Zero by 2040 is also close to the recent call by leaders of The B Team, who run some of the world’s largest companies, who are urging a global goal of net-zero greenhouse-gas emissions by 2050. [9]


When it comes to policy we can now get specific, and turn the 2040 Imperative into a roadmap.

For transportation, it requires an organized plan to shift all modes of transport to 100% renewable energy by 2040. This would drive municipal and regional goals for increased walking, cycling, carsharing, transit and rail. It would set provincial and national goals for EV uptake, require the electrification of all of Canada’s railways, and require the transformation of long-distance freight. For details, both for transportation and for other sectors mentioned below, see Part Two in two weeks.

For buildings, it requires zero emissions from all new buildings, which could start by 2020, allowing five years for the industry to learn zero-carbon building techniques, and it requires zero emissions from existing buildings by 2040 through a nationwide program to retrofit every building for greater energy saving and renewable energy for heat.

For electricity, it requires a federal Clean Energy Plan that would help the provinces to close down all coal and gas-fired power plants by 2040 and ramp up conservation, renewables and power storage to take their place, including geothermal for base-load power.

For industry, it requires a major drive to help companies improve their energy efficiency, and replace the use of coal and gas with biomass or hydrogen.

For Alberta’s oil sands, it requires factoring zero by 2040 into all National Energy Board decisions, freezing production at the current level (helped by the current low price of oil), denying licenses for all new pipelines, closing down the last operation by 2040, and firming up the financial and legal requirements for boreal forest restoration.

For the economy as a whole, it requires (among many things) eliminating all subsidies and tax breaks that support fossil fuels, shifting them to clean energy, and doing everything necessary to accelerate the increase in solar, wind, geothermal and other renewables that will be needed to replace fossil fuels by 2040.


All of the above could be announced as noble intentions, with targets and goals. The way to make it real, however, so that the 25 Mt a year reduction actually happens, is for a government agency to hold an annual auction in which any company wishing to import or extract a fossil fuel must bid to buy a permit for a share of a fossil fuel market that is now shrinking by 25 Mt a year, in defiance of whatever the market wants.

The auction would put a price on carbon. That, in turn, would create a need to protect low-income people against fuel poverty, either by distributing rebate cheques or by establishing a system of carbon rationing to ensure that the steadily falling availability of fossil fuels for heat and fuel is shared out equitably. More on this in Part Two, in two weeks.

Many economists would view such a rapid annual reduction as a recipe for economic disaster, arguing that it would cause economic growth to grind to a halt. By arguing thus, they and all others who argue for a slow and cautious approach to the climate crisis are saying in effect that the risk of economic stress for this generation is more important than the risk of civilizational collapse and the disruption of nature for the next generation.

Fortunately, most economic models don’t take account of planned non-market changes or rapid technological transition. The same warnings against rapid action might have been issued in the 1880s in response to the horse manure crisis, which created a huge public health hazard on the streets of Europe’s cities—a crisis that would be solved by a technological game-changer with the advent of streetcars and motorcars.

Smart governments will plan for the transition, just as they planned for railways in the 19th century, war in 1914 and 1939, highways and automobiles in the 1950s, and oil and gas extraction in the 1970s and onwards. The solar age is coming, and they will organize to make it happen.

Jobs will be lost, just as they were lost in the horse economy a hundred years ago, but new jobs can be created by applying entrepreneurial skill to research and development, innovation, business start-up support, cooperative economic development and a host of other initiatives, encouraged by financial and economic initiatives such as public banking, basic income, work-sharing, employee share ownership, profit-sharing, tax reform, a financial transactions tax, and the closure of the world’s tax havens.

There are many factors that indicate that a zero carbon economy powered by 100% renewable energy would be stronger and more resilient than an economy that depends on oil and gas. Homes that need 90% less heat will have lower fuel bills; electric cars will cost far less to run; cities with good cycling, transit and carsharing will make it easy for people not to own a car. Tackling the climate crisis will be far cheaper than not tackling it, and many climate solutions will increase available income, strengthening the economy. [10]

Continue reading here.