(John Kemp is a Reuters market analyst. The views expressed are his own)
By John Kemp
LONDON, May 17 (Reuters) - Budgets are made to be broken - especially when they are written by politicians.
Unfortunately it seems the world is on course to break the carbon budget that scientists and policymakers agree is necessary to limit the rise in global temperatures to less than 2 degrees Celsius.
If governments were really committed to limiting the rise in temperatures to 2 degrees, two-thirds of the currently known oil, coal and gas reserves would have to be left in the ground, according to the International Energy Agency (IEA).
But it is not clear anyone is taking the target seriously. In the last 12 months, the top 200 oil, gas and mining companies allocated up to $674 billion to finding and developing even more reserves, according to the Climate Tracker Initiative.
The shares of petroleum and mining companies listed on New York, London and other stock exchanges value them as if all these resources will be extracted and burned.
There is a "gross inconsistency between current valuations for fossil fuel assets and the path governments have committed to take", according to Nicholas Stern, a leading adviser to Britain's government on the economics of climate change.
TOTAL CARBON BUDGET
In 2010, countries in the United Nations Framework Convention on Climate Change confirmed their intention to limit emissions of greenhouse gases to hold the rise in average temperatures to less than 2 degrees above pre-industrial levels.(Cancun Agreements, 1/CP.16 I 4)
Two degrees is "considered the threshold for preventing dangerous anthropogenic interference with the climate system", the IEA wrote in its "2012 World Energy Outlook".
Limiting warming to 2 degrees with a probability of 50 percent implies the atmospheric concentration of greenhouse gases must be stabilised at about 450 parts per million of carbon dioxide (CO2) equivalent, according to the IEA and scientific advisers on the Intergovernmental Panel on Climate Change (IPCC).
The 450 parts per million target implies there is a maximum amount of carbon dioxide that can be emitted and of fossil fuels that can be burned - something both policymakers and climate campaigners have termed the global "carbon budget".
"Carbon dioxide emissions from fossil fuels and land-use change in the first half of this century must be kept below 1,440 billion tonnes of CO2 equivalent," according to the IEA.
"Since a total of 420 billion tonnes of CO2 have already been emitted between 2000 and 2011, and we estimate that 136 billion tonnes will be emitted from non-energy related sources in the period up to 2050, a maximum of 884 billion tonnes can be emitted by the energy sector from 2012 to 2050," the IEA concluded.
Climate campaigners have come up with similar estimates. "The available budget is 900 billion tonnes of CO2 for an 80 percent probability to stay below 2 degrees and 1,075 billion tonnes for a 50 percent probability," according to the Carbon Tracker Initiative's report "Unburnable Carbon 2013: wasted capital and stranded assets".
Given the substantial amount of uncertainty surrounding the measurement of emissions and their precise impact on temperatures, it is safe to assume the carbon budget is around 1,000 billion tonnes of CO2 equivalent between now and 2050.
Energy-related CO2 emissions were just over 31 billion tonnes in 2011 and rising, IEA figures show.
COOKING THE PLANET
There are more than enough fossil fuels to cook the planet many times over. Current proven and probable reserves of oil, gas and coal (resources which have been found and are estimated with a probability of more than 90 percent and 50 percent respectively) would emit the equivalent of 2,860 billion tonnes of CO2 if they are all burned, according to the IEA.
"More than two-thirds of current ... fossil fuel reserves cannot be commercialized in a 2 degree world before 2050," IEA cautions.
Nicholas Stern explains in a forward to the "Unburnable carbon 2013" report: "If we burn all current reserves of fossil fuels, we will emit enough CO2 to create a prehistoric climate, with Earth's temperature elevated to levels not experienced for millions of years.
"Smart investors can already see that most fossil fuel reserves are essentially unburnable ... They can see that investing in companies solely or heavily relying on constantly replenishing reserves of fossil fuels is becoming a very risky decision," Stern claims.
The facts suggest otherwise. "The markets appear unable to factor in the long-term shift to a low-carbon economy into valuations and capital allocation," the Climate Tracker Initiative admits. "Capital needs to be redirected away from high-carbon options."
"The bulk of (the $674 billion investment) was derived from retaining earnings - pointing to the duty of shareholders to exercise stewardship over these funds so they are deployed on financially gainful opportunities consistent with climate security.
"The current balance between funds being returned to shareholders, capital invested in low-carbon opportunities and capital used to develop more reserves needs to change," Climate Tracker Initiative argues.
"Unburnable carbon 2013" sets out recommendations for finance ministers, regulators, actuaries, advisers and investors to help force a re-evaluation of the risks of investing in more fossil fuel production and to push capital towards lower-carbon alternatives.
Bill McKibbin's 350.org is mobilising a grass-roots campaign to convince pension funds investing on behalf of state, municipal and college employees in the United States to divest their holdings in fossil fuel companies. The aim is to force change by organising an investment boycott similar to those mounted against South Africa during apartheid, and more recently against Iran.
350.org demands fossil fuel companies stop exploring for new hydrocarbons, stop lobbying in Washington and state capitols, and "pledge to keep 80 percent of their current reserves underground forever".
IS ANYONE LISTENING?
So far, the concepts of a carbon budget and of a maximum amount of fossil fuels that can be burned have not got much traction with policymakers, corporations or the public.
Earlier this month, the average daily concentration of greenhouse gases measured at the Mauna Loa Observatory in Hawaii passed 400 parts per million. It is rising at about 2 parts per million every year, yet the milestone generated comparatively little comment and relative indifference from the public and officials.
Voters and politicians seem unconvinced that the 450 ppm target can or should be achieved.
"Collectively, humanity has yawned and decided to let the dangers mount," columnist Martin Wolf observed in the Financial Times on Monday ("Why the world faces climate chaos" May 15).
"We will watch the rise in greenhouse gases until it is too late to do anything about it," he concluded
Wolf went on to explain the seven reasons for inaction and speculate on what would be necessary to spark a real effort to change.
Apocalyptic warnings about the dangers will not work, he said. If action is required, they must be replaced by a much more positive vision of a prosperous and low-carbon future.
In the meantime, "there is no political will to do anything real about the process driving our experiment with the climate. Yes there is talk and wringing of hands. But there is, predictably, no effective action," he notes sadly.
Campaigners such as 350.org and the Climate Tracker Initiative hope to change that indifference by pushing the issue back up the agenda.
Investors and fossil fuel companies are gambling that they will not succeed, and politicians are not serious about enforcing a combustion cap. (editing by Jane Baird)