The cost of keeping global warming in check is “relatively modest,” but only if the world acts quickly to reverse the buildup of heat-trapping gases in the atmosphere, the head of the UN’s Intergovernmental Panel of Climate Change (IPCC) said on Sunday.
Such gases, mainly carbon dioxide from the burning of fossil fuels, rose on average by 2.2 percent per year between 2000 and 2010, driven by the use of coal in the power sector, UN officials said as they launched the IPCC report on measures to fight global warming.
Without additional measures to contain emissions, global temperatures will rise about 3 degrees to 4?C by 2100 compared with current levels, the panel said.
“The longer we delay, the higher would be the cost,” IPCC chairman Rajendra Pachauri told reporters after the panel’s weeklong session in Berlin. “But despite that, the point I’m making is that even now, the cost is not something that’s going to bring about a major disruption of economic systems. It’s well within our reach.”
The IPCC projected that shifting the energy system from fossil fuels to zero or low-carbon sources, including wind and solar power, would reduce consumption growth by about 0.06 percentage points per year, adding that did not take into account the economic benefits of reduced climate change.
The IPCC said the shift would entail a near-quadrupling of low-carbon energy — which in the panel’s projections included renewable sources, as well as nuclear power and fossil fuel-fired plants equipped with technologies to capture some of the emissions.
US Secretary of State John Kerry called it a global economic opportunity.
“So many of the technologies that will help us fight climate change are far cheaper, more readily available and better performing than they were when the last IPCC assessment was released less than a decade ago,” Kerry said.
The IPCC said large changes in investments would be required. Fossil fuel investments in the power sector would drop by about US$30 billion annually, while investments in low-carbon sources would grow by US$147 billion. Meanwhile, annual investments in energy efficiency in transport, buildings and industry sectors would grow by US$336 billion.
The IPCC avoided singling out any countries or recommending how to share the costs of climate action in the report, the third of a four-part assessment on climate change.
Though it is a scientific body, its summaries outlining the main findings of the underlying reports need to be approved by governments.
In Berlin, a dispute erupted over whether to include charts that showed emissions from large developing countries are rising the fastest as they expand their economies. Developing countries said linking emissions to income growth would divert attention from the fact that historically, most emissions have come from the developed nations, which industrialized earlier.
In the end the charts were taken out of the summary, but would remain in the underlying report, which was to be published later in the week, officials said.
Counting all emissions since the industrial revolution in the 18th century, the US is the top carbon polluter. China’s current emissions are greater than those of the US and rising quickly. China’s historical emissions are expected to overtake those of the US in the next decade.
The ambition of a new climate agreement next year that would rein in emissions after 2020 is to keep warming below 1.2?C compared with today’s levels. Global temperatures have already gone up 0.8?C since the start of record-keeping in the 19th century.