What 2 degrees would look like

Despite the optimism of climate gurus like Robert Stavins and Trevor Houser with the results of Cancun, a temperature rise of 2 degrees is almost certain and adaptation is here to stay. That's why these two videos by CCAFS (a new CGIAR initiative focused on climate change, agriculture and food security) are interesting. They feel overly scripted and a bit contrived (hasn't the Sahara been shifting back and forth for centuries, even before it had any help from us?), but nevertheless provide some anecdotal illustrations of what agriculture looks like when temperature varies by two degrees. There is a lot of adaptation (e.g. growing trees to shade coffee plants) and also some shift to livestock cultivation as hotter temperatures make land more arid and marginal. Maybe the latter is another sign that we should all just go paleo...

New IFPRI modeling and report

IFPRI just published a new report entitled "Food Security, Farming and Climate Change to 2050: scenarios, results, policy options" with new outputs from their robust IMPACT partial equilibrium model. The punch line is:

Our analysis suggests that up to 2050, the challenges from climate change are “manageable,” in the sense that well-designed investments in land and water productivity enhancements might, conceivably, substantially offset the negative effects from climate change. But the challenges of dealing with the effects between 2050 and 2080 are likely to be much greater than those to 2050. Starting the process of slowing emissions growth today is critical to avoiding a calamitous post-2050 future.

The last sentence is a very important one. While attention (including my own) may be drifting toward adaptation, the fact that significant climate change will almost certainly occur is not a binary determination. It could be bad or very bad, depending on the level at which atmospheric greenhouse gases stabilize (or not), and thus in the long run mitigation still has an extremely important role to play. The challenge, of course, is that both the distraction of adaptation and the long time horizon make it very difficult to muster a critical mass of political will behind mitigation actions that impose any sort of economic pain whatsoever.

Adaptation to center stage

One of my favorite recent papers is by Michael Roberts and Wolfram Schlenker (regular readers may have noticed me regularly plugging it here, here, here, here, and here). Congrats to Michael and Wolfram on being mentioned prominently by The Economist in this week's long article on climate adaptation.

The entire article is pretty good and worth a read, particularly for its dogged effort to parse out climate impact and adaptation, and subsequent honesty where this proves impossible. For example:

Melissa Dell of the Massachusetts Institute of Technology and her colleagues argue that in developing countries GDP growth has been lower in hotter years than in cooler ones. This may carry over into longer-term increases in temperature. The mechanism is obscure: it may simply be that overheated people work less hard. That can be seen either as adaptation or as a worrying impact, slowing down the economic growth which is the surest foundation for other, more positive adaptations.

Not only is adaptation hard to distinguish from impact, investments in response are harder to classify:

Whereas investments in mitigation are fairly easy to understand—build windmills not coal-fired power stations, and so on—those in adaptation are harder to grasp. Action on climate bleeds into more general development measures.

The article overall is pessimistic

The fight to limit global warming to easily tolerated levels is thus over.

and while I wish I disagreed, and hold out for better-than-expected outcomes from Cancun this week, my inner skeptic and pragmatist are pushing me hard to shift focus - professional and personal - toward adaptation.

Sea rise not that scary?

That's the case that climate adaptationist Bjorn Lomborg (don't call him a skeptic) makes at Project Syndicate, because we've dealt with it already:

Imagine that over the next 70 or 80 years, a giant port city – say, Tokyo – found itself engulfed by sea levels rising as much as 15 feet or more... Without a vast, highly coordinated global effort, how could we possibly cope with sea-level rises on that order of magnitude?

Well, we already have. In fact, we’re doing it right now. Since 1930, excessive groundwater withdrawal has caused Tokyo to subside by as much as 15 feet, with some of the lowest parts of the downtown area dropping almost a foot per year in some years. Similar subsidence has occurred over the past century in a wide range of cities, including Tianjin, Shanghai, Osaka, Bangkok, and Jakarta. In each case, the city has managed to protect itself from such large sea-level rises and thrive.

Lomborg cites research research claiming that over 95% of the world's coastal population is urban, making rising oceans no big deal.

A 20-foot rise in sea levels (which, not incidentally, is about ten times more than the United Nations climate panel’s worst-case expectations) would inundate about 16,000 square miles of coastline, where more than 400 million people currently live... [and] the vast majority of those 400 million people reside within cities, where they could be protected relatively easily, as in Tokyo.

Off the top of my head, I'd challenge this with Bangladesh, which has 160 million people and is very low-lying:

Is it really fair to assume Dhaka has an easy out just because it's "urban"? Maybe Jakarta has coped with rising seas, but Indonesia's per capita GDP is still 3x that of Bangladesh.

Lagos and Karachi are two other poor coastal megacities that would be worth doing the same analysis for.

Update: I just had dinner with someone from Bangladesh who confirmed that the idea that rising seas won't hit Bangladesh hard is preposterous. First, there are millions of people living in low-lying, non-urban areas (especially hundreds of islands in the Ganges Delta). Second, much of the productive agricultural land is similarly low and is already suffering from soaring salinity in many areas. So it seems that the underlying analysis is weak, and Lomborg himself should be doing better quality control of the sources he chooses to cite.

Update 2: A few relevant numbers to refine our back-of-the-envelope: 46% of Bangladeshis live within 10 meters of the average sea level, and the country is only 27% urban. So it seems very unlikely that Lomborg's math that "only ~15 million people would need to be relocated [over the course of the century]" can possibly be right.

Cost of climate change and adaptation

Via Climate Progress, a new report has sized both the risks posed by climate change and the costs and benefits of effective adaptation.

A report from the Economics of Climate Adaptation Working Group released today indicates that climate risks could cost nations up to 19% of their GDP by 2030, with developing countries most vulnerable. The report concludes, however, that cost effective adaptation measures already exist that can prevent between 40 and 68 percent of the expected economic loss with even higher levels of prevention possible in highly target geographies. [emphasis mine]

The report is authored by McKinsey and a group of business and non-profit sponsors. The headline numbers are interesting, and I will be interested to see how various constituencies react.

Romm vs. Lomborg on climate change adaptation

In the WSJ, Bjorn Lomborg thinks a "technology-led effort" featuring adaptation and geo-engineering will be more effective than high carbon taxes to reduce emissions, and he cites a number of studies supporting his position. For example

Taking a variety of natural, so-called market adaptations into account, the Carraro research shows we will acclimatize to the negative impacts of global warming and exploit the positive changes, actually creating 0.1% increase in GDP in 2100 among the member countries of the Organization for Economic Cooperation and Development. In poor countries, market adaptation will reduce climate change-related losses to 2.9% of GDP. This remains a significant, negative effect. The real challenge of global warming lies in tackling its impact on the Third World. Yet adaptation has other positive benefits. If we prepare societies for more ferocious hurricanes in the future, we also help them to cope better with today's extreme weather.

... and...

Remarkably, Mr. Bickel finds that about $9 billion spent developing this so-called marine cloud whitening technology might be able to cancel out this century's global warming. The benefits—from preventing the temperature increase—would add up to about $20 trillion.

As I've said before, the potential unintended consequences of geo-engineering freak me out. As for adaptation, Joe Romm is scornful of the "adaptation trap":

What is the cost of “adaptation”? It is almost incalculable. The word is a virtually meaningless euphemism in the context of catastrophic global warming. That is what the deniers and delayers simply don’t understand. On our current emissions path, the country and the world faces faces multiple catastrophes, including:

• Staggeringly high temperature rise, especially over land — some 10°F over much of the United States
• Sea level rise of 5 feet, rising some 6 to 12 inches (or more) each decade thereafter
• Permanent Dust Bowls over the U.S. SW and many other heavily populated regions around the globe
• Massive species loss on land and sea — 50% or more of all life
• Unexpected impacts — the fearsome “unknown unknowns”
• More severe hurricanes — especially in the Gulf

He then uses Hurricane Katrina as an example of the huge challenges of adaptation (and, commendably, doesn't fall into the enticing but superficial "global warming caused Katrina" meme). He concludes:

If we won’t adapt to the realities of having one city below sea level in hurricane alley, what are the chances we are going to adapt to the realities of having all our great Gulf and Atlantic Coast cities at risk for the same fate as New Orleans — since sea level from climate change will ultimately put many cities, like Miami, below sea level?

I don't know the answer here - these are both smart guys who care passionately about finding the right solution to a major global issue. My hunch is that geo-engineering will not provide us with a simple silver bullet, and that the collective action problem will likely end up with temperatures rising and adaptation necessary to some degree. But that is not an excuse to junk all attempts to moderate our emissions by introducing a price on carbon (shorthand for all GHGs) that harnesses the power of markets as an ally. In this fight we need all the allies we can get.

Update: In a guest rebuttal at Climate Progress (cleverly titled "The Bjorn Irrelevancy"), Dr. Bill Chameides, dean of the Nicholas School of the Environment at Duke, dissects Lomborg's argument and accuses him of cherry-picking only those forecasts and research results which support his point.

Two new IFPRI briefs on ag and climate change

Via Blog World Hunger, IFPRI has just released two new policy papers on adapting to climate change in Africa. Here are the headline conclusions:

"Economywide Impacts of Climate Change on Agriculture in Sub-Saharan Africa":

The paper uses two scenarios: the first doubles the irrigated area in Sub-Saharan Africa by 2050 but keeps total crop area constant; and the second scenario increases both rainfed and irrigated crop yields by 25 percent for all Sub-Saharan African countries. Due to the limited initial irrigated area in the region, an increase in agricultural productivity achieves better outcomes than an expansion of irrigated area. Both scenarios help lower world food prices, stimulating national and international food markets.

"Soil and Water Conservation Technologies: A Buffer against Production Risk in the Face of Climate Change?":

Results show that soil and water conservation technologies have significant impacts on reducing production risk in Ethiopia and could be part of the country’s climate-proofing strategy. However, results also show that one-size-fits-all recommendations are not appropriate given the differences in agro-ecology and other confounding factors.

IFPRI does great work, and these sound like solid contributions; nevertheless, adaptation to climate change (particularly in Africa and South Asia) has a looooong road ahead.