IPCC

Recent report published projecting values of sea-level rise

As anyone who reads my posts knows, I am a big fan of the IPCC reports. They are the best summary of what the scientific community knows about climate change and how confidently we know it.

A recent article (subscription required, sorry) in Science suggests that some scientists view the IPCC as overly cautious:

In the latest report, its fourth since 1990, the IPCC spoke for scientists in a calm, predictably conservative tone (Science, 9 February, p. 754). It is, after all, an exhaustive, many-tiered assessment of the state of climate science based exclusively on the published literature. In IPCC's Working Group I report on the physical science of climate, 600 authors contributed to an 11-chapter report that drew 30,000 comments from reviewers. The report was in turn boiled down to a 21-page "Summary for Policymakers" (SPM). Its central projection of sea-level rise by the century's end -- 0.34 meter -- came within 10% of the 2001 number. And by getting a better handle on some uncertainties, it even brought down the upper limit of its projected range, from 0.89 to 0.59 meter.

The SPM did add that "larger values [of sea-level rise] cannot be excluded." Whatever has accelerated ice-sheet flow to the sea, the report said, might really take off with further warming -- or not. "Understanding of these effects is too limited" to put a number on what might happen at the high end of sea-level rise, it concluded. Lacking such a number, the media tended to go with the comforting 0.34-meter projection or ignore sea level altogether.

I have two conflicting views of this.

The ‘in it for the money’ theory of climate science doesn’t pan out

We have all heard the following argument: in order to get funding for research, the scientific community is forced to produce alarmist predictions of climate change.

There's a lot wrong with this argument. But it recently occurred to me that it doesn't even make sense. In the latest IPCC reports, what the scientific community said is that our understanding of climate change is quite good (although not "settled"). This does nothing to build up research funding.

The former: Not good for the latter

How climate change will disproportionately affect the world's poor is a message making the rounds of late, after the publication of the second IPCC report earlier this year. How climate change policies, such as carbon taxes, will either help or hurt the poor is also a topic we've been discussing of late.

Now researchers at the University of Minnesota have assessed the impact of an increased dependence on biofuels on the developing world ... and the outlook isn't good.

In short, conflating food and energy lands us in a quagmire in which corn (and ethanol) prices are still tethered to oil:

Observed warming since 1990 is greater than the models predicted

An article in the May 4 issue of Science shows that observed warming in the 16 years since 1990 is greater than predicted by models.

Perhaps models are underestimating future climate change. That would be bad news.

"Recent Climate Observations Compared to Projections"

We present recent observed climate trends for carbon dioxide concentration, global mean air temperature, and global sea level, and we compare these trends to previous model projections as summarized in the 2001 assessment report of the Intergovernmental Panel on Climate Change (IPCC). The IPCC scenarios and projections start in the year 1990, which is also the base year of the Kyoto protocol, in which almost all industrialized nations accepted a binding commitment to reduce their greenhouse gas emissions. The data available for the period since 1990 raise concerns that the climate system, in particular sea level, may be responding more quickly to climate change than our current generation of models indicates.

Those who argue that great uncertainty exists in our knowledge of climate need to recognize that uncertainty cuts both ways -- things could be worse than we think just as easily as they could be better.

Summarizin’ summaries, summarily

Here is the second half of my summary of the IPCC summary (PDF):

Energy Efficiency:

It is often more cost-effective to invest in end-use energy efficiency improvement than in increasing energy supply to satisfy demand for energy services. Efficiency improvement has a positive effect on energy security, local and regional air pollution abatement, and employment.

(In buildings):

Energy efficiency options for new and existing buildings could considerably reduce CO2 emissions with net economic benefit. Many barriers exist against tapping this potential, but there are also large co-benefits (high agreement, much evidence).

By 2030, about 30 percent of the projected GHG emissions in the building sector can be avoided with net economic benefit.

Interview with Pachauri

ThinkProgress has an interview with Dr. Rajendra Pachauri, chairman of the IPCC. Worth a listen.

Summaries of a summary — the new black?

Finally, below is the first half of my summary of the IPCC summary (PDF):

In 2030 macro-economic costs for multi-gas mitigation, consistent with emissions trajectories towards stabilization between 445 and 710 ppm CO2-eq, are estimated at between a 3% decrease of global GDP and a small increase, compared to the baseline. However, regional costs may differ significantly from global averages (high agreement, medium evidence).

In 2050 global average macro-economic costs for multi-gas mitigation towards stabilization between 710 and 445 ppm CO2-eq, are between a 1% gain to a 5.5% decrease of global GDP. For specific countries and sectors, costs vary considerably from the global average (high agreement, medium evidence).

It ain’t pretty

I want to highlight a few points from the IPCC's Mitigation Report (PDF).

First, even the most stringent global greenhouse gas targets can be met at a cost of a mere 0.1% of GDP per year!

While the report is not explicit about when action should be taken, it does say that:

In order to stabilize the concentration of GHGs in the atmosphere, emissions would need to peak and decline thereafter. The lower the stabilization level, the more quickly this peak and decline would need to occur.

The Center for American Progress and I have encouraged stabilizing atmospheric CO2 concentration at 450 ppm and/or a temperature rise of 2 degrees Celsius over the pre-industrial era. That said, according to one of the report's charts (see page 22), reductions aimed to cut emissions 85% by 2050 must be initiated before 2015.

And maybe sooner. According to the IPCC:

Decision-making about the appropriate level of global mitigation over time involves an iterative risk management process that includes mitigation and adaptation, taking into account actual and avoided climate change damages, co-benefits, sustainability, equity, and attitudes to risk. ... if the damage cost curve increases steeply, or contains non-linearities (e.g. vulnerability thresholds or even small probabilities of catastrophic events), earlier and more stringent mitigation is economically justified.

Tucked into footnote 37 of the report, there's a brief discussion of feedbacks that could certainly, and dangerously, be categorized as a non-linear, vulnerable threshold to which we are blind.

The message of the report is clear. Countries must act, and soon. We can choose to stabilize the climate and still maintain prosperous economies. But we must make a financial commitment that just hasn't materialized. We've been going backwards. The IPCC reports:

Government funding in real absolute terms for most energy research programmes has been flat or declining for nearly two decades (even after the UNFCCC came into force) and is now about half of the 1980 level.

At this point, that is unacceptable. The policies the IPCC has recommended have great potential and low cost. The world needs make the political and economic commitments to curb emissions. The time to act is now.

This post was created for ClimateProgress.org, a project of the Center for American Progress Action Fund.

Climate change justice is contentious

As this round of the IPCC unfolds, developing countries are scurrying to relieve themselves of any major responsibility for historic emissions and, consequently, aggressive mitigation policies.

For example, China has requested inserting language that formally recognizes the percentage of emissions for which developed countries are responsible -- 95 percent from the pre-industrial era until 1950, and 77 percent from 1950 to the start of the millennium.