IPCC Confirms Link Between Extreme Weather Events and Climate Change

A definitive report from the the U.N. Intergovernmental Panel on Climate Change (IPCC) released today says it now certain that human emissions of greenhouse gases and warming aerosols like black carbon are increasing the frequency and intensity of extreme weather by putting more heat energy into the climate system. 

The report urges countries to develop disaster management plans to adapt to the certainty of ever more frequent, intense extreme weather events: blistering heat waves, heavier rainfall and more floods, stronger cyclones, landslides and more intense droughts.

The UN report comes just a week after the International Energy Agency (IEA) released a similar grave report, warning the world has five years before it locks in irreversible climate change. 

New York State released its own climate study this week, predicting that with expected sea level rise and stronger storms, future hurricanes could flood the tunnels into Manhattan within an hour, put one-third of the city underwater, and destroy the city’s water supply from salt water entering the system. These climate-induced impacts are expected to begin within a decade. 

The cost of the 14 major US weather disasters in 2011 is a forecast at $53 billion, according to the National Climate Data Center. 

"These climate change impacts have become so clear and so close now that we need fast, aggressive mitigation if we hope to avoid the worst consequences," says Durwood Zaelke, President of the Institute for Governance & Sustainable Development.

"Fast mitigation is the best adaptation," Zaelke adds. "Fast mitigation means cutting short-lived climate forcers, including black carbon, ground-level ozone, and hydrofluorocarbons, or HFCs, used in refrigeration.  Cutting these non-CO₂ climate forcers can be done quickly and inexpensively using existing technologies and in most cases existing laws and institutions."  This can cut the rate of global warming in half for several decades and the rate of warming in the Arctic by two-thirds, according to a report by the UN Environment Program and the World Meteorological Organization. 

In September, the EU passed a resolution calling for fast action to reduce non-CO2 climate forcers including black carbon soot, hydrofluorocarbons (HFCs), methane, and ground-level ozone, which together are responsible for 50% of atmospheric conditions causing climate change.

Zaelke states, "States and cities need to start thinking how they will pay for adaptation and for cleaning up after extreme weather events, including following the precedent set by states in their battle with tobacco companies, which included lawsuits to recoup health care costs the states were paying to care for victims of tobacco injuries."  The lawsuits resulted in a historic $350 billion national tobacco settlement.

Addressing climate change also requires cutting emissions of CO₂, the principal greenhouse gas, protecting and expanding forests and other "carbon sinks" that remove and store CO₂, and developing other CO₂ removal strategies to draw down excess CO₂ from the atmosphere on a time scale of decades, rather than the millennial time scale of the natural CO₂ removal process. 

Greenhouse Gases Still Rising

Global carbon emissions grew at their fastest rate since 1969 last year, as countries rebounded from economic recession. Greenhouse gas concentrations in the atmosphere increased  1.4% last year and 29% since the boom years of the 1990s.

Carbon emissions were responsible for 80% of the increase and human activities, such as the use of fossil fuels and agriculture, were the major causes of the emissions rise, says the World Meteorological Organization in its annual Greenhouse Gas Bulletin.

And much more potent methane and nitrous oxide emissions are growing. Nitrogen-based fertilizers are the largest source of nitrous oxide, which traps about 300 times the heat of CO2, "profoundly affecting the nitrogen cycle," says the report.  

More nitrous oxide is detected in the northern hemisphere, where the bulk of fertilizer is used, showing the impact of petroleum-based, conventional agriculture.

The research shows a discernible decrease in CFCs in the atmosphere because of the Montreal Protocol, which banned them. But they’ve been replaced by HCFCs, which are also potent greenhouse gases, and although their rise is so far small, it is growing rapidly in the atmosphere.