Saturday, July 26, 2014

A Washington State climate policy that does the carbon math

Question: What would a climate policy look like that actually meets carbon reduction goals determined by science?

Answer: Carbon pollution from fossil fuels would be cut far faster and far deeper than is contemplated in climate policies now on the books or under consideration.

Washington State is currently moving toward a climate policy to cap statewide carbon emissions.  Gov. Jay Inslee’s Carbon Emissions Reduction Taskforce (CERT) will hear the proposed policy design in a meeting Tuesday.  It will inform the governor’s proposal to legally limit carbon pollution.  He is expected to put it before the legislature next year.

The effort builds on non-binding carbon goals set in 2008 legislation, SB6001. The bill, even when it passed, did not meet what science indicated was needed to stem global warming. It set a goal of only 50% carbon reductions by 2050 when 80% was the generally understood target. Now the science has moved even further, and global warming impacts are accelerating beyond the expectations of even just a few years ago.  Washington’s carbon goals must move with the science, and the times.

A recent article by James Hansen and his colleagues sets the bar for what a carbon reduction policy should require. Arguably the world’s top climate scientist, Jim Hansen has authored a landmark.  Of his many seminal journal articles, this one may prove to be the most important.   “Assessing ‘Dangerous Climate Change,’” provides the carbon math that must guide policy.

The key points:

The source of global warming is an energy imbalance.  More solar heat is entering the Earth’s atmosphere than leaving it.

The way to even the balance is by reducing the capacity of the atmosphere to trap heat.  That means cutting emissions of heat-trapping gases, primarily carbon dioxide.  Achieving balance will require reducing atmospheric CO2 to 350 parts per million (ppm). CO2 is now around 400ppm and climbing fast. 

Achieving 350ppm by 2100 will require holding total fossil fuel carbon emissions to 500 billion metric tons, or gigatons (GtC), and soaking another 100GtC from the atmosphere into trees, other plants and soils.  Humanity has released 370GtC, so our remaining carbon budget is 130GtC

Staying within our carbon budget requires immediate carbon reductions of 6% per year.  The longer we delay the higher that annual percentage becomes and the greater will be the warming. 

The graph below illustrates how choices we make now will echo across the centuries.  The dotted line is the 350ppm point at which the atmosphere has crossed the line back into balance.  The left-hand graph shows the effect of the Hansen goals for 6% annual carbon reductions and natural carbon storage.  The planet is back in balance around 2100.  Contrast this with the solid blue line in the right-hand graph.  Even the still ambitious target of 5% a year delayed until 2020 pushes the balance point two centuries into the future to 2300. Note that the 450ppm carbon limit that has generally been accepted as the standard carbon boundary, the green line, does not produce climate balance even by 2500. Some curves reach out a millennium. If anything illustrates the urgency of deep carbon cuts beginning now, it is this graph:  

The scientists are not blind to the political difficulties. They note, “It is distressing that, despite the clarity and imminence of the danger of continued high fossil fuel emissions, governments continue to allow and even encourage pursuit of ever more fossil fuels. Recognition of this reality and perceptions of what is ‘politically feasible’ may partially account for acceptance of targets for global warming and carbon emissions that are well into the range of ‘dangerous human-made interference’ with climate. Although there is merit in simply chronicling what is happening, there is still opportunity for humanity to exercise free will. Thus our objective is to define what the science indicates is needed, not to assess political feasibility (emphasis mine).”

Nonetheless, Hansen and his colleagues add, deep and rapid carbon cuts are not beyond the realm of practicality.  “. . . it is not obvious to us that there are physical or economic limitations that prohibit fossil fuel emission targets far lower than 1000 GtC (the generally accepted goal in global climate negotiations – P.M.) even targets closer to 500 GtC. Indeed, we suggest that rapid transition off fossil fuels would have numerous near-term and long-term social benefits, including improved human health and outstanding potential for job creation.”

I asked a long-term colleague and one of the best carbon brains around, Roel Hammerschlag, to calculate the implications of a 6% annual reduction curve for Washington State in comparison with current goals.  Here is Roel’s graph:

The blue line shows the carbon emissions trajectory without policy change.  The dotted red line depicts Washington State carbon goals set under its 2008 climate bill,  The orange line plots the 6% annual carbon reductions curve for which climate science calls. 
Here are tables comparing the two sets of goals:

Annual CO2 Emissions in Metric Tons


Percentage Reduction in Emissions Compared to 1990


Note that the graph calls for its steepest emissions cuts between now and 2030.  This underscores the importance of immediate action. Each year adds to the accumulation of atmospheric carbon.  So hitting annual targets for carbon reduction as soon as possible is crucial to stem the carbon buildup and long-term effects.

Washington State is only a small part of the global picture.  But Washington is also a significant state in the nation that has put the most human-originated carbon into the atmosphere. The U.S. is responsible for 26% of the total. Washington also claims to be a climate leader.  To truly lead, Washington must adopt goals and policies that line up with the science.  This means going beyond SB6001 to adopt the Hansen 6% goal and with it an agenda to move Washington State off fossil fuels much more rapidly than current plans contemplate.

Rapid transition to 100% renewable energy, a comprehensive effort to retrofit most buildings for energy efficiency, and an accelerated move to electric vehicles are elements of the agenda.  Investments in forest carbon, soil-building agriculture and wetlands restoration add to the biological carbon storage side of the Hansen prescription.  Washington with its rich natural resources can make a disproportionate contribution in this area. The Northwest Biocarbon Initiative is advancing carbon-soaking land use practices.

It is not hard to understand why Washington must set a high bar for carbon cuts now.  Just think about 2100.  About how closely we are connected to the future. 

A 10-year-old in 2014 will have a child in 2029 when she is 25. 

Her child will bear her grandchild in 2054 when she herself is 25.

Her grandchild will have a daughter, also at 25, in 2079

Today's 10-year-old may well live to 2100. She would be 96. Her child will be 71 then. Her grandchild will be 46, her great grandchild 21.   

If we move now to achieve 6% annual carbon emissions cuts as soon as humanely possible and to leverage our landscape for biocarbon storage, their families could live in a world that has veered away from the worst danger.  Climate change will still be severe but beginning to stabilize.  

Or they might live in a world that remains in the danger zone for generations more, and where climate balance will not be achieved for centuries.   What we leave them depends on the choices we make today.  Washington State can choose to set carbon goals clearly indicated by science and model a climate leadership agenda for the world.  If that seems impossibly out of reach, just consider that 21-year-old. 

No comments:

Post a Comment