Climate change: part 2 (the reckoning)

Now that we’ve talked about how climate change is happening and carbon emissions are increasing rapidly (in the previous post), let’s discuss what’s being done and what can be done to address this global ecological crisis.  I hope this isn’t too heavy for pre-holiday fare.

In September, the Intergovernmental Panel on Climate Change (IPCC, an international organization of climate scientists) released an important report. They argued that climate change is “unequivocal” and that the “dominant cause” has been human actions in pouring greenhouse gases into the atmosphere. Moreover, even if the world begins to moderate greenhouse gas emissions, warming is likely to cross the critical threshold of 2°C by the end of this century, which would have serious consequences including sea level rises, arctic ice melts, heatwaves, major changes to rainfall, and extreme weather events.  If crucial steps aren’t taken, “tipping points” and thresholds will soon be reached and climatic changes will be irreversible.

It is also important to note that the most vulnerable and poorest peoples–who are not responsible for the crisis–are the most likely to be affected by climate change.  Numerous islands and coastal regions are already being threatened.  Developing nations are unable to cope with extreme weather (such as the recent typhoon in the Philippines), droughts, and water and food shortages.  Climate change is an environmental justice issue, though ultimately it will affect us all and our future generations.

COP19

A month ago, an important climate summit, the 19th “Conference of the Parties” meeting of the UN Framework Convention on Climate Change (COP 19), occurred in Warsaw. International representatives from nearly 200 countries discussed these issues and attempted to continue to negotiate for a new global climate accord by 2015. In addition, developing nations were seeking compensation for the “loss and damage” that they will almost certainly face, while rich countries (which produce most of the carbon emissions) were avoiding taking blame, making commitments, or allowing any statements in UN climate documents that could be used against them in the future. It became so bad that over 800 members of environmental groups and NGOs (including Friends of the Earth, Greenpeace, WWF, Oxfam, the International Trade Union Confederation, 350.org, and the Pan African Climate Justice Alliance) staged an unprecedented walkout of the talks. In the end, very little was achieved, though a deforestation agreement was made and plans were made for the following meeting next year in Peru.

How does the US fit in all this?  Unfortunately, the US is among the countries avoiding making serious commitments to address climate change and rising carbon missions.  President Obama finally laid out a climate action plan earlier this year, nearly 25 years after NASA climate scientist Jim Hansen testified before Congress about evidence for global warming. The plan includes a number of sound policy measures and plans to reduce greenhouse gas emissions 17% below 2005 levels by 2020, especially with new EPA standards for power plants.  This is a good start, but even with this, we’ll still likely reach 3°C warming.  Far deeper reductions are needed (such as with a carbon “fee-and-dividend” system, which we can discuss later). Furthermore, environmental justice must be a part of the plan (see this Union of Concerned Scientists blog post), since the burden of the impacts of climate change fall disproportionately on low-income communities and communities of color.

Climate change: part 1

I’d like to say a bit about climate change. It’s an issue that I’m passionate about, as it’s one of the most important global crises facing us today, and there will be plenty more to write about in later posts.

As a possible future for our own planet, it’s useful to think of Venus.  Although there are no Venusians to ask about it, we can infer what happened to Venus based on observations of its surface and atmosphere.  Venus and Earth likely had similar early atmospheric compositions, but on Earth the carbon is mostly in the crust.  In Venus’s case, its atmosphere is mostly CO2, and it appears to have suffered a “runaway” greenhouse gas effect.  Venus’s surface temperature of nearly 500° C is due to its atmosphere’s depth and CO2 content.  In order to reach Venus-like conditions on Earth, massive amounts of CO2 would need to accumulate and would need to get rid of its oceans via escape of hydrogen to space, which would take at least hundreds of millions of years.

Mariner_10_image_of_Venus_cloud_tops_medium

Nonetheless, it only takes much smaller amounts of CO2 emissions and much less time to change the biosphere and harm human and other life on earth.  It is already happening.  And because the climate responds slowly, so far we’ve only felt about half of the effect of the greenhouse gases that are already in the air.

According to the Scripps Institution of Oceanography (which is a few blocks from here at UCSD), the daily mean concentration of CO2 in the atmosphere surpassed 400 parts per million (ppm) in May this year.  The Keeling curve below documents the dramatic rise of this potent greenhouse gas over the last half century.

mlo_full_record

More CO2 in the atmosphere means that more of it is absorbing and trapping the infrared radiation of sunlight near the Earth’s surface, gradually raising the temperature.  There are many effects and evidence of climate change, but one key one is that surface temperatures on Earth are increasing.  Last year was the hottest year on record and this year is the seventh hottest. According to climate scientists, 350 ppm should be our goal in order to prevent runaway climate change, but it will require concerted international efforts to substantially reduce carbon emissions to safe levels.

A global problem requires global solutions.  But what can be done and is being done about climate change (including at the UN and by US policies) will be the subject of “part 2”.

Finally, for those of you who’d like more eloquent writing about these issues, check out this essay from Carl Sagan’s Cosmos.