Development in a Changing Climate
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CO2 emissions

Carbon Dioxide Levels Reach Unprecedented Highs: But Catastrophic Climate Change Can Still be Avoided

Alan Miller's picture

Graph showing CO2 levels for the last 800,000 years. - Photo: Courtesy of World Meteorological Organization
Graph shows concentrations of atmospheric Co2 for the last 800,000 years, with measurements, starting from 1958, made at Mauna Loa in Hawaii. - Image courtesy of World Meteorological Organization

Scientists monitoring atmospheric concentrations of CO2 from a mountaintop in Hawaii recently reported that the presence of this greenhouse gas exceeded 400 parts per million (ppm) for the first time in at least three million years – a period when temperatures were much warmer than today. The significance of this seemingly dry statistical trend is stunning as reported in the New York Times:

From studying air bubbles trapped in Antarctic ice, scientists know that going back 800,000 years, the carbon dioxide level oscillated in a tight band, from about 180 parts per million in the depths of ice ages to about 280 during the warm periods between. The evidence shows that global temperatures and CO2 levels are tightly linked.

In addition to the location in Hawaii, several other Global Atmosphere Watch stations from the Arctic to the Equator reported CO2 concentrations exceeding 400ppm.

Experts believe that in order to limit warming to 2°C – a goal based on expected impacts – concentrations should rise to no more than 450 ppm, a level we may reach in only about 25 years based on current trends.

China Phase-Out of Ozone Damaging Chemicals Brings Climate Benefits

Karin Shepardson's picture

A slew of air conditioning units in a building. - Photo: Shutterstock​

Also available in Chinese

Last month, China was granted US$95 million to reduce its production of hydro-chlorofluorocarbons (HCFCs), substances that are used primarily for cooling, refrigeration, and the manufacture of foam products. The funding comes from the Multilateral Fund (MLF) of the Montreal Protocol, because HCFCs deplete the ozone layer and are controlled under the Protocol. With access to these funds, between now and 2015 China will reduce its production of HCFCs by 10%, or 47,000 metric tons from 2010 levels, allowing it to meet the first reduction targets set by the Protocol.

This alone is worth celebrating because China is the world's largest producer of HCFCs. Nearly 50% of its production is consumed by other developing countries, all of whom also face HCFC consumption reduction targets under the Protocol. Herein lies one secret to the Protocol’s success: its ability to regulate both production and consumption worldwide simultaneously, putting into practice an economist’s dream to tackle both supply and demand in tandem. By addressing the supply side of the problem through support to China’s production phase-out, the demand side - in China and in developing countries around the world - can build a sustainable HCFC consumption phase-out response. The ozone layer, and human and environmental health, will all be the better for it.

Celebrating 25 Years of the Montreal Protocol - and Looking Ahead

Rachel Kyte's picture

The world’s leaders set a high bar when they adopted the Montreal Protocol, which has helped protect the Earth’s protective ozone layer for the last 25 years. Even with its ambitious goals, the treaty won universally ratification – 197 parties have agreed to legally binding reduction targets to phase out ozone-depleting gases, and they have stuck to them.

The result: we, as a global community, have almost completely phased out the use of 97 substances that were depleting the ozone layer.

It’s a success worth celebrating, but we can’t rest on our laurels. We phased out CFCs, once used for cooling most refrigerators on the planet, but some of their replacement gases have become a climate change problem we still have to contend with.

The CFCs story showed that the world can move at speed and scale to reduce environmental threats. Scientists realized that CFCs were depleting the ozone layer in 1974. The ozone hole over Antarctica became common knowledge in the 1980s and helped drive global action which led to the Montreal Protocol being adopted in 1987.

Tar sands: The story behind the headlines

Alan Miller's picture

The complexity of climate change issue is a challenge for most mainstream media, which increasingly seek the shortest possible sound bite to interest an audience with a very limited attention span. Yet a recent example illustrates the importance of looking past the headlines to understand the importance and true meaning of scientific announcements.  The article featured the optimistic headline: “New study finds oil sands fuels would cause imperceptible temperature rise.” 

This declaration understandably attracted considerable attention from climate policy-watchers because Canadian oil sands (also commonly referred to as “tar sands” reflecting the heavy, molasses like quality of the substance) are the resource proposed for transmission via the controversial Keystone XL pipeline recently denied a permit by the Obama Administration. (Oil sands deposits have also been found in Russia, Venezuela and Kazakhstan, but a majority of identified reserves and virtually all commercial production are in Canada.)  

Some advocates for developing the oil sands see their use as essentially a national energy security issue, maintaining the pipeline is an important step forward toward fulfilling the long cherished dream of US energy independence, not to mention the potential to reduce or at least stabilize gasoline prices: ``Is US Energy Independence Finally Within Reach”, National Public Radio, March 7, 2012.

To be sure, the promise of lower gasoline prices and energy security are strong considerations. But an ongoing debate continues as to whether or not this economically attractive resource can be extracted, refined, and distributed without unacceptable environmental harm. This is why an otherwise academic analysis by Neil Swart and Andrew Weaver at the University of Victoria in British Columbia proved newsworthy. They calculated the global temperature rise that would result from the carbon dioxide released by burning currently proven reserves of Canadian oil sands: Neil Swart and Andrew Weaver, “The Alberta oil sand and climate,” Nature Climate Change, Feb. 19, 2012.