So here's a message from those of us who have built things: Everything takes longer that it seems like it should. If, for example, we decide that we must replace domestic air travel with high-speed electric rail systems, we should get started laying track this week if we expect it to replace a system as large as domestic air transport by 2040. In fact, when you add in all the delays in funding and opposition from the NIMBYs, greedheads, and vested interests—it probably would have been a good idea to start laying new track about 15 years ago.
This little bit of reality is why I get so frustrated with the well-meaning who assume that if we could only get our political decision-making in line, the problems would be solved. Yes it's a start but it would only be a start. You still have to build the new systems and GET THEM TO WORK.
My other hope was that we could build the new green / solar society with the fuels we still have. Since we have already passed Peak Oil and are looking at less than 27 years to rebuild our civilizations, this solution looks increasingly impossible with each passing day. The time for position papers and global conferences for the concerned has passed. The time for laying track and building net-zero houses is now or never.
Carbon Budget Message In IPCC Report Reveals Daunting ChallengePosted: 10/04/2013
From Climate Central's Andrew Freedman:
Within the voluminous report from the U.N. Intergovernmental Panel on Climate Change (IPCC) published on Sept. 27 is a conclusion as sobering as any climate change warning to date.
The world is currently on track to emit enough greenhouse gases by about 2040 to exceed the globally agreed upon temperature target of 3.6°F (commonly referred to in international negotiations as the 2°C target), beyond which the risks of “dangerous” consequences of global warming escalate.
In laying out a global cumulative carbon budget, the IPCC has for the first time endorsed the view of climate activists and scientists who have warned that countries cannot burn the world’s known reserves of fossil fuels without sending the climate system into a tailspin.
If climate change exceeds the temperature target, scientists warn, there is a greater risk that the world’s ice sheets will be destabilized, leading to sharply rising seas, and increasing climate extremes such as droughts, heat waves and floods, which could pose daunting challenges for food and water availability for growing populations. In less likely worst-case scenarios, feedback loops within the climate system could disrupt ocean currents.
Staying under that temperature target is a daunting challenge, given the lack of progress to date in arresting emissions of climate-warming greenhouse gases. In order to meet the temperature target, the IPCC report made clear, the reality is that much of the planet’s known and economically recoverable supply of fossil fuels will need to be left in the ground.
Living Within a Carbon Budget
Based on studies published during the past several years, the IPCC found that in order to have at least a 66 percent chance of limiting global warming to, or below, 3.6°F above pre-industrial levels, no more than 1 trillion tonnes of carbon can be released into the atmosphere from the beginning of the industrial era through the end of this century.
The IPCC report estimates that we’ve already used 531 billion tonnes of that budget as of 2011 by burning fossil fuels for energy as well as by clearing forests for farming and myriad other uses. That means we’re on the wrong side of the carbon budget, with 469 billion tonnes left.
According to a 2009 study published in the journal Nature, burning all proven and economically recoverable fossil fuel reserves — never mind other potential new fossil fuel discoveries — would pump another 763 billion tonnes of carbon into the atmosphere. That would be enough to exceed the carbon budget and, most likely, set the globe on track to sail past the temperature target.
What’s worse is that the budget may even be smaller since emissions other than carbon dioxide (CO2) also contribute to global warming. Factoring in some of these shorter-lived climate pollutants, such as nitrogen oxide and soot, brings the overall cumulative budget down from 1 trillion tonnes of carbon to 800 billion tonnes.
With that in mind, the remaining budget is even smaller, leaving just 269 billion tonnes of carbon left. To stay within the budget, global emissions would have to peak by 2020, and then become negative – with more carbon being taken out of the atmosphere by plants and the oceans than is put into the air each year — by 2090.
The IPCC report also said that a possible release of greenhouse gases from thawing permafrost and methane hydrates — which are “not accounted for in current models” — would shrink the remaining budget even further.
“I think the numbers themselves are a very depressing reminder of how time is running out quickly,” said Kelly Levin, a senior associate at the World Resources Institute, a nonpartisan research group.
Specifically, the scenario involving just 269 billion tonnes of carbon left carries “a grave, grave message,” Levin said in an interview.
Projections of global mean sea level rise over the 21st century relative to 1986–2005 from the combination of the computer models with process-based models, for greenhouse gas concentration scenarios. The assessed likely range is shown as a shaded band. The assessed likely ranges for the mean over the period 2081–2100 for all scenarios are given as coloured vertical bars, with the corresponding median value given as a horizontal line. Click image to enlarge. Credit: IPCC Working Group I.
That’s because the current rate of oil and gas production coupled with the lack of global political momentum to reduce emissions appears to have us on course to burn right through the carbon budget like a teenager at the mall with their weekly allowance.
Because CO2 can linger in the Earth’s atmosphere for decades to centuries, the carbon budget offered in the IPCC report is based on cumulative carbon emissions, or the total amount emitted over time. According to the report, there is a near linear relationship between cumulative carbon emissions and the peak global mean temperature that such emissions will cause. This means that limiting cumulative emissions are key to preventing global average temperatures from exceeding the target.
The cumulative carbon budget is akin to a climate change credit card, where every month you charge more than you pay off leads to ever increasing unpaid balances. With a credit card, the longer you keep overcharging, the larger the bill you have at the end, and the more difficult it becomes to pay down. Similarly, the longer it takes for carbon emissions to peak, the steeper emissions will have to fall in order to keep warming temperatures in check.
As with a credit card, which involves interest rate charges, there’s an important catch with the climate budget: the climate change that results from today’s emissions will remain locked into the climate system, leaving a climate debt to future generations to deal with. For example, the IPCC report found that sea levels would continue to rise for centuries after the climate is stabilized at a given level of warming, and air temperatures would remain elevated long after emissions reach their peak as well.
To keep that debt from mounting, the 2009 Nature paper found that less than a quarter of the available and economically recoverable fossil fuel reserves can be burned between 2009-2050 in order to meet the 3.6°F temperature target. That’s in line with the IPCC’s numbers, and would require a dramatic change of course for the global economy. more