Climate Change, Nature, Science

Climate Change Speeds Up Snowmelt and Drought Risk Grows in West

Snow melts on Mount Rainier and water runs off the Wilson Glacier and disappears under the NIsqually Glacier.
Snow melts on Mount Rainier and water runs off the Wilson Glacier and disappears under the NIsqually Glacier. Photo: Jim Culp | FlickrCC.

In the Western parts of North America, mountains play a big part in the water cycle. Colorado and Washington snowmelt contributes to how much water is captured in the ground, used by plants, or makes its way into groundwater.

It also joins streams and flows downhill to cities and rural areas. Climate change can have a big impact on snowmelt as global average temperatures rise.

Water on mountains deposited in the form or rain or snow either evaporates or flows downhill. The way that water collects on the mountains has an impact on water flow. Rainwater tends to disappear more quickly, while snow takes longer to melt and allows for a more consistent, and longer, addition of water to streams and so watersheds.

The result is that, as we saw in Washington in 2015, if it doesn’t snow enough, you don’t get as much water coming down from the mountains in the spring and summer, and you end up with a drought.

According to a study performed by researchers in Colorado, rising temperatures can have a hug impact on how much water makes it from the mountains to the lowlands. Higher temperatures generally mean less snow, though not always less precipitation. But as we’ve already seen, snowmelt has a more gradual effect, and if water isn’t running downhill, it needs to be brought from reservoirs and other sites.

The key take away from the study is that water resource managers need to know how different forms of precipitation interact with their local environments, in order to best budget for water consumption during growing seasons.

Although the researchers have more work to do on the subject, this initial study should help western states and provinces deal with potential droughts a little better.

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Climate Change, Science

Glacial Melt and Erosion Leads to More Volcanic Activity

U-shaped valley in Leh Valley, Ladakh, NW Indian Himalaya. The glacier visible at the head of the valley is the last remnants of the formerly much more extensive valley glacier, which carved this valley.
U-shaped valley in Leh Valley, Ladakh, NW Indian Himalaya. The glacier visible at the head of the valley is the last remnants of the formerly much more extensive valley glacier, which carved this valley. Photo: Dan Hobley | WikiMedia.

According to a recent study by researchers at the University of Cambridge, we’ve been underestimating the CO2 levels at the end of the last ice age. It turns out that melting glaciers lead to an increase in volcanic activity, something they have known about for a while, but so does increased erosion, a side effect of that melting which they hadn’t thought of before.

Melting glaciers reduce pressure on the Earth’s mantle, allowing for greater magma production and more volcanic eruptions. That’s because rocks under less pressure melt at lower temperatures. Erosion contributes to this as well, as parts of the Earth’s crust change in depth; those regions put less pressure on the mantle.

And of course, increased volcanic activity unleashes more CO2 into the atmosphere, which results in more melting, and so on. It is this system, which brings an end to an ice age, a process that generally lasts about 20,000 years or so. Glacial and interglacial periods (we’re in the latter now) tend to last in 100,000-year cycles.

Because the timescales are so vastly different, the researchers warned readers not to draw too strong a connection between these systems and the glacial melting that were seeing now as side effect of human activity. Global warming is leading to increased glacial melt, and increased erosion, both form those glaciers and in other ways as well.

That could mean that, as time goes by, we will see an increase in volcanic activity around the world, which could have a lot of negative consequences. For one, that means more CO2 in the atmosphere, but it also means the potential for massive destruction and huge loss of life, depending on the activity in question. If the rebuilding effort afterward leads to greener communities moving forward, it may help offset some of the damage, but at what cost?