Warming climate can mean more rain, flooding in Northeast - WMUR Manchester
Climate change: Warming means more rain, flooding in Northeast
Warming climate can mean more rain, flooding in Northeast
Some New Hampshire communities have received months' worth of rain in just weeks
It has been a summer of extreme weather, from record heat in the Southwest to very heavy rainfall and flooding in New England.
Some Granite State communities have received well over three months' worth of rain in just the past few weeks.
As the climate continues to warm, heavy rain and flooding will become more likely in New Hampshire.
>> Watch: How is climate linked to extreme weather, and what can be done?
Connecting climate change to floods can be tricky. Not only do many weather- and human-related factors play into whether a flood occurs, but limited data on the floods of the past make it difficult to measure them against the climate-driven trends of floods today.
However, through research in the Northeast, it has become increasingly clear that climate change has influenced several of the water-related variables that contribute to floods. In other words, while the warming world might not induce floods directly, it exacerbates many of the factors that do.
While all the rain that has fallen in New Hampshire this summer can't be directly attributed to climate change, the extremes are happening more and worsening.
This summer, some communities in New Hampshire, such as Newport and Keene, have received more than 15 inches of rain in about a month and a half. Normally, that much rain falls over the course of four or five months.
Some of the hardest hit areas of the state have been in the Upper Valley, Monadnock and Sunapee regions, as well as the northern Lakes Region up to the Mount Washington Valley.
The pattern the Northeast has been stuck in has been relentless, with the jet stream overhead or just to the south, allowing system after system to pour down rain.
As the climate warms, storms will dump more water. At higher temperatures, the air can hold more moisture content, which can lead to an increase in precipitation intensity, duration and frequency.
Basically, because of global warming, when it rains, it pours more, and flash flooding can occur.
Dr. Jonathan Winter, of Dartmouth College, explains how extreme weather is linked to climate change:
Related Knowledge Center: Climate science
What began as a theory in the 1890s — that industrial emissions of carbon dioxide could increase global temperatures — had progressed to a scientific fact a century later. Scientists across a range of disciplines are studying the impact of the still-growing concentration of carbon dioxide and other so-called “greenhouse gases” in the atmosphere as they call for industrial and governmental policies to slow, then halt, the warming of the planet.