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Transforming Transportation in Our Polluted, Congested Cities

Karin Rives's picture

 Kim Eun Yeul / World Bank

Cities are the world’s engines of economic growth, but they also account for 70 percent of global greenhouse gas emissions and many metropolitan areas struggle with traffic congestion, lost productivity, public health problems and traffic deaths due to inadequate public transportation.

How can we make our cities livable, inclusive, prosperous and green?

Increasing Flood Risks Create Major Challenges for World's Coastal Cities

Stéphane Hallegatte's picture

 NOAA via Wikimedia
The flooding of New Orleans, caused by Hurricane Katrina in 2005, illustrates the vulnerability of cities that are highly dependent on coastal defenses. Photo: NOAA [http://commons.wikimedia.org/wiki/File:Katrina-new-orleans-flooding3-2005.jpg]

Increasing flood risks create a major political and institutional challenge for the world’s coastal cities, as ambitious and proactive action at the local level over the next decades will be needed to avoid large-scale flood disasters. However, the implementation of flood risk management policies meets many obstacles.

In a recent study written with colleagues Colin Green, Robert Nicholls and Jan Corfee-Morlot as part of an OECD project on urban vulnerability, we estimate how flood risks could change in the future in 136 coastal cities, in response to increasing population and wealth, local environmental change, and climate change. We find that because current flood defenses and urbanization patterns have been designed for past environmental conditions, even a moderate change in sea level is sufficient to make them inadequate, thus magnifying flood losses to catastrophic levels. If no action is taken to reduce flood vulnerability, most coastal cities would become inhospitable and dangerous places to live, with annual losses in excess of US$1 trillion dollars.

What can be done?

Our analysis suggests that upgrading defenses could mitigate these losses and the impacts of rising sea levels. However, these upgrades need to include a package of risk management policies. First, coastal defenses should make use of the protection the environment can offer for free: Marshes, seagrass beds, coastal and kelp forests, and coral reefs provide natural buffers that absorb the energy from waves and storms, making it easier and cheaper to protect urban development. In addition artificial constructions are also required to provide full protection. We are not only talking about dykes: a city surrounded by dykes will need pumping systems to drain rainfall water, and a harbor will need moving barriers to let ships in and out of the port.

Be afraid. Be very afraid

Dan Hoornweg's picture

Earlier this week, I read an article in Scientific American that had an ominous warning ‘global warming is close to becoming irreversible’. In typical cautionary climate-speak there’s a hope stated that “we can cap temperature rise to two degrees”. This is followed by a more subtle message, “we are on the cusp of some big changes”.

‘On the cusp of changes’ is an understatement. There are a half-dozen possible tipping points, crossing any of which gets us into scary unchartered territory. Ocean acidity and coral die-off; drying the Amazon rainforest; run away growing fossil fuel use; loss of ice sheets; large scale melting of permafrost: and the biggest tipping point of all – our amazing inability to come anywhere near an agreement limiting global GHG emissions and warming.

The article argues that unless we seriously curb the rate of growth of GHG emissions within the next 10 years, we will cross tipping points that lead to significant and irreversible global warming. And yet, all that was agreed at COP17 in Durban last year is for countries to reach an agreement by 2015 for action that will not start until 2020. Too little too late, according to the science.

The world will likely only see 450 ppm CO2 concentrations from our rear-view mirror as we hurtle down the express lane to at least 550 ppm CO2 and a 5 degree warming. What the article doesn’t say is that we will need to figure out how to geo-engineer some sort of amelioration. Good luck with that. We can’t agree on the much easier aspects of limiting GHG emissions; how will we ever agree on something as complicated as managing the planet’s climate?

Should cities wait for a global climate deal?

John Roome's picture

We all know that the quality of the air we breathe has an immense impact on the health of the people and the economies of developing countries. Poor air quality can also threaten the economic competiveness of cities. Increasingly global companies consciously chose to locate in livable cities. We’re already seeing that in Asia.  A 2006 survey by the Hong Kong’s Chambers of Commerce showed that worsening air quality was beginning to affect investment decisions of corporations.

 

I spent two days last week at the Suntec Center in Singapore attending the Better Air Quality conference. This year’s theme was Air Quality in a Changing Climate. The link between the two – improved air quality and reducing climate change is sometimes not so apparent and I am glad the conference was making the link clearer. Climate change impacts all countries but the World Development Report 2010 estimates that some 75-80 percent of the damages caused by a changing climate will be borne by developing countries. If we are to limit global warming to about 2 degrees Celsius above the pre-industrial level, we will all need to invest massively in energy efficiency, renewable energy sources, and more efficient transportation.

 

Combating air pollution is one area where it is possible to capture important co-benefits with respect to climate change. By taking specific measures, we can simultaneously achieve local health and welfare benefits (including related to air quality) while also reducing greenhouse gas (GHG) emissions. While it is important to strive for a global deal on climate change, there are a number of things that cities can do in the interim to simultaneously reduce local environmental impacts and reduce carbon emissions. And by demonstrating on the ground some things that can work in this regard, cities can position themselves to access any global carbon financing that might become available as part of a global deal.