Earlier this week, the world marked its 44th Earth Day, a day to celebrate this beautiful planet, our only home in the entire universe. But amidst our celebrations, anyone who’s followed the news since last Earth Day knows we also need to sound an urgent note of warning for earth’s future.

CO2 level breaks modern record

On April 7, 2014, the concentration of climate-warming CO2 in the atmosphere hit a new global high of 402 parts per million (ppm) based on readings from a mountaintop monitoring station in Hawaii (www.weather.com/news/science/environment/carbon-dioxide-rises-highest-levels-800000-years-20140410). Greenhouse gas (GHG) levels have not been this high in 800,000 years when the Arctic was free of ice and sea levels were 40 meters higher than today.

In 2013, we emitted more carbon (including in the U.S.) than in any previous year. (www.ipcc.ch/pdf/ar5/pr_wg3/20140413_pr_pc_wg3_en.pdf), up an estimated 2.1% over 2012 and a 61% increase since 1990. The rate at which emissions are being released grew more quickly in the last decade than in each of the three previous decades thanks to a growing energy demand and an increase in coal use.

Temperatures

NASA scientists say 2013 tied 2006 and 2009 for the seventh warmest year since the 1880s. Nine of the 10 warmest years on record have occurred since 2000, with 2005 and 2010 ranking as the warmest years on record (the other warmest year in the top 10 was 1998.)

Averaged over all land and ocean surfaces, global temperatures have warmed roughly 1.53°F (0.85ºC) from 1880 to 2012. Scientists warn that beyond 3.6°F (2°C), the earth risks catastrophic warming that may become unstoppable.

Climate refugees

This month near Papua New Guinea, 40 large families with 2,000 people are abandoning their home on the Carteret Islands. They are the world’s first entire community to be displaced by climate change. High tides now wash away their crops, and salt water from rising sea levels has poisoned what remains. The islands will be completely submerged by 2015 (earthfirstjournal.org/newswire/2014/04/06/first-official-climate-change-refugees-evacuate-their-island-homes-for-good/).

Three reports from the world’s preeminent scientific body on climate change

Since last Earth Day, the Intergovernmental Panel on Climate Change (IPCC) has issued three sobering reports. The first, issued in September 2013, looked at the physical science. It concluded climate change is now everywhere, its impacts are already unfolding, and humans are the “dominant cause.”

The second report, released in March 2014, looked at impacts and how people might adapt. It warned that that adaptation alone does not offer adequate protection, and that we risk pushing our climate system toward abrupt, unpredictable and potentially irreversible changes. It emphasized that world leaders have only about 15 years left to reduce carbon emissions enough to avoid catastrophic warming.

And the third report, just out this month, focused on economic costs of mitigation, and how governments can work together to moderate climate change. The report presents grounds for hope that the cost of mitigation would not cripple the global economy and may be less than commonly assumed. However, in terms of both adaptation and mitigation, the sooner we act, the lower the cost.

These IPCC reports, which together synthesize the evidence and the conclusions of thousands of scientific papers by hundreds of scientist/authors, make clear that climate change is not a political issue, that its effects are real, and that we must begin to view climate change as a risk management issue. All the evidence points to certain risk, and yet uncertainties remain, among them, what is the tipping point beyond which changes to earth’s climate system may become permanent? This scenario of risk and uncertainty brings to mind the commonsense need for insurance, and indeed a sensible insurance plan already exists in the form of the Copenhagen Climate Accord. In 2009, 114 countries agreed that warming this century must not increase by more than 3.6°F (2°C). To reach this goal, emissions will need to fall by 40 to 70% by 2050. We believe this is eminently achievable, if we have the will.

As another Earth Day passes, we call on the U.S. to step up and become a leader rather than a naysayer in the fight against climate change. We call on Washington to support the 194 nations that are trying to broker a new climate treaty by the end of 2015. We call on our elected leaders to pass legislation to establish a climate budget and to approve a carbon tax to incentivize the reduction of CO2 emissions. We urge those who run our fossil fuel industries to search their souls and ask whether it is moral to reap vast private profits from wrecking the climate. (We applaud Harvard University for becoming the latest institution to pledge to divest its endowment funds from fossil fuel companies, and we urge other institutions and pension plans to join the divestment movement). We call on the president to say “no” to the XL Pipeline, because as one noted climate activist says, if it is built it will likely be “game over” for the climate. Finally, we call on every citizen to take steps to reduce your own carbon footprint (biofuel.tamu.edu/publications/tensteps.pdf).

Time is ticking away. We need to be able to report some real progress by next year’s Earth Day. Then we may really have something worth celebrating.