On Friday, scientists at Scripps Institution of Oceanography, at the University of California, San Diego, recorded CO2 levels higher than the world has seen in over 800,000 years.

From atop the Mauna Loa volcano on the big island of Hawaii—the oldest continuous carbon dioxide measurement station in the world—a reading of just over 400 parts per million (ppm) was recorded this Friday. A similar measurement was made at the National Ocean and Atmospheric Administration (NOAA) station, also in Hawaii. This reading pushes us well past the 350 ppm target scientists say we should stay below if a global temperature rise of 2 degrees Celsius is to be avoided.

This interactive infographic, originally published on The Guardian, gives a more detailed account of just what 400ppm looks like and how these measurements compare to our historic average:

Dr. Charles David Keeling of Scripps began measuring emissions in 1958.

A constant record of CO2 levels has been kept since Keeling developed the now standard ‘Keeling Curve.' It is the most accurate method of measuring carbon dioxide in the air to date and there are several global stations using it to keep an eye on rising emissions. The earliest measurements recorded 310 ppm in the late 1950’s and the global average before the 19th century's Industrial Revolution was 280 ppm.

According to James Butler of NOAA’s Earth System Research Laboratory, a CO2 reading of 400 ppm “[is] mainly important as a milestone that marks a steady progress of increasing carbon dioxide in the atmosphere.”

Marking such progress has been crucial in understanding the global rise of CO2 concentrations and demonstrating the need for improved environmental practices on an international level.

By studying the bubbles trapped in glacier ice, scientists have deduced that the atmosphere hasn’t had this much carbon dioxide in it for 800,000 to 5 million years.

The numbers will dip somewhat when the Northern Hemisphere reaches the height of summer and the leafy forests drink up some of the CO2 in the air. However, according to NOAA, once emitted, the extra “CO2 in the atmosphere and oceans remains for thousands of years.”

This news has hit many scientists hard. Maureen E. Raymo from the Lamont-Doherty Earth Observatory at Columbia University told the New York Times, “It feels like the inevitable march toward disaster.”

Dr. Keeling’s son, Ralph Keeling took over the research at Scripps after his father’s death in 2005. He fears that the levels could reach 450 ppm in the next 25 years if nothing is done to reduce emissions.

Many major contributors to global carbon emissions – like the United States, China and Canada – have no binding national targets and no immediate plans to make them. Without clear guidelines in place, limiting the warming and extreme weather events associated with increased carbon in the atmosphere will be difficult, and likely expensive.

“There’s no stopping the CO2 from reaching 400 ppm,” Ralph Keeling says. “That’s now a done deal. But what happens from here on still matters to climate, and it’s still under our control. It mainly comes down to how much we rely on fossil fuels for energy.”

Infographic Credit:@theduncanclark / The Guardian / Kiln

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This is a guest post by sustainable energy economist, Mark Jaccard. It was originally published on his blog, Sustainability Suspicions.

On May 7th 2013, I was among twelve Canadian climate scientists and energy experts who sent a letter addressed to Natural Resources Minister the Hon. Joe Oliver.

As professionals who have devoted our careers to understanding the climate and energy systems, we are concerned that the Minister’s advocacy in support of new pipelines and expanded fossil fuel production is inconsistent with the imperative of addressing the climate change threat. We are going to have to wean ourselves off our addiction to fossil fuels. Thus our choices about fossil fuel infrastructure carry significant consequences for today’s and future generations.

Readings of atmospheric CO2 are approaching a new milestone of 400 ppm — a reminder of the rapidly shrinking amount of “space” remaining before we risk committing ourselves to increasingly unmanageable and costly levels of climatic change.

Here is the text of the letter:

The Honourable Joe Oliver, P.C., M.P.

Minister of Natural Resources

Parliament Hill

Sir William Logan Building, 21st Floor

580 Booth Street

Ottawa, ON K1A 0E4

May 7, 2013

Dear Minister Oliver,

As climate scientists, economists and policy experts who have devoted our careers to understanding the climate and energy systems, we share your view that “climate change is a very serious issue.”

But some of your recent comments give us significant cause for concern. In short, we are not convinced that your advocacy in support of new pipelines and expanded fossil fuel production takes climate change into account in a meaningful way.

Avoiding dangerous climate change will require significantly reducing our reliance on fossil fuels and making a transition to cleaner energy.

The infrastructure we build today will shape future choices about energy. If we invest in expanding fossil fuel production, we risk locking ourselves in to a high carbon pathway that increases greenhouse gas emissions for years and decades to come.

The International Energy Agency’s (IEA) “450 scenario” looks at the implications of policy choices designed to give the world a fair chance of avoiding 2˚C of global warming. In that scenario, world oil demand is projected to peak this decade and fall to 10 per cent below current levels over the coming decades. The IEA concludes that, absent significant deployment of carbon capture and storage, over two-thirds of the world’s current fossil fuel reserves cannot be commercialized. Other experts have reached similar conclusions.

We are at a critical moment. In the words of the U.S. National Academy of Sciences, “each additional ton of greenhouse gases emitted commits us to further change and greater risks.” The longer we delay the transition to low-carbon economy, the more drastic, disruptive and costly that transition will be. The implication is clear: the responsibility for preventing dangerous climate change rests with today's policymakers.

The IEA also warns of the consequences of our current path. If governments do little to address emissions, energy demand will continue to grow rapidly and will continue to be met mostly with fossil fuels — a scenario that the Agency estimates could likely lead to 3.6˚C of global warming.

Yet it is this very dangerous pathway  — not the “450 scenario” linked to avoiding 2˚C of global warming — that you seem to be advocating when promoting Canadian fossil fuel development at home and abroad.

If we truly wish to have a “serious debate” about climate change and energy in this country, as you have rightly called for, we must start by acknowledging that our choices about fossil fuel infrastructure carry significant consequences for today’s and future generations.

We urge you to make the greenhouse gas impacts of new fossil fuel infrastructure a central consideration in your government’s decision-making and advocacy activities concerning Canada’s natural resources.

We would be very happy to provide you with a full briefing on recent scientific findings on climate change and energy development.

Thank you for your consideration of these important matters.

Sincerely,

J.P. Bruce, OC, FRSC

James Byrne

Professor, Geography

University of Lethbridge

Simon Donner

Assistant Professor, Geography

University of British Columbia

J.R. Drummond, FRSC

Professor, Physics and Atmospheric Science

Dalhousie University

Mark Jaccard, FRSC

Professor, Resource and Environmental Management

Simon Fraser University

David Keith

Professor, Applied Physics, Public Policy

Harvard University

Damon Matthews

Associate Professor, Geography, Planning and Environment

Concordia University

Gordon McBean, CM, FRSC

Professor, Centre for Environment and Sustainability

Western University

David Sauchyn

Professor, Prairie Adaptation Research Collaborative

University of Regina

John Smol, FRSC

Professor, Canada Research Chair in Environmental Change

Queen’s University

John M.R. Stone

Adjunct Research Professor, Geography and Environment

Carleton University

Kirsten Zickfeld

Assistant Professor, Geography

Simon Fraser University

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