rainfall

Climate change, snow and ice, and water resources

pgleick — Wed, 20 Feb 2013 10:28:44 +0000

Climate change, snow and ice, and water resources

One of the reasons that climate change is such a big issue is because the global climate is an integral part of the Earth’s entire ecosystem, tied to so many of the big and little things that society cares about. Figuring out how all these complicated pieces tie together is hard, as is linking these pieces together in the minds of the public so that we – and our policy makers – can grasp the true implications of a changing climate and plan for them. Because this is so important, I expect that many of my future posts here will address this issue, but let me start with one example: the relationships between climate, snow, ice, and water resources.

Some of my earliest research on climate and water (my doctorate in 1986 evaluated the regional hydrologic impacts of climate change) showed that one of the most critical impacts of climate change would be changes in the snow/rain dynamics in mountains. Since then, more and better research has confirmed and strengthened our understanding of how vulnerable water systems – and especially mountain regions – are to climate changes. Indeed, we already see impacts in the form of disappearing tropical and high-latitude glaciers and ice caps, changing rainfall patterns, and increased water content in the atmosphere, not to mention the growing influence of climate change on the frequency and intensity of some extreme events.

The climate is incredibly complex. But, in fact, many climate impacts are actually pretty simple to understand. Let’s focus for the moment on just one piece of the climate change picture: temperature. We know the Earth is warming up because of human activities. This fact alone would mean that more of the precipitation that falls will be rain and less of it will be snow, even if total precipitation stays the same (it won’t, by the way). Higher temperature also means that what does fall as snow will melt faster and run off earlier into our rivers and streams. And any ice sitting on the ground will melt faster than it would have otherwise.

Snow. Glaciers. Icecaps. All of these are vulnerable to climate change, especially rising temperature. This isn’t theory. It’s fact. In our heavily videoed, satellite-observed, cell-phone-connected world, the evidence can be delivered instantly to the screen you’re looking at right now.

Take the Himalayas. The Hindu Kush-Himalayan region (HKH) spans thousands of miles and seven countries (Afghanistan, Bangladesh, Bhutan, China, India, Nepal, and Pakistan) *[Ed. oops: eight! See comment #1 below for correction] and contains many of the largest glaciers in the world. The Himalayas are the headwaters of some of the most important rivers as well – including the Ganges, Indus, Brahmaputra, Salween, Mekong, Yellow, and Yangtze. These rivers provide drinking and irrigation water for at least one and a half billion people. A recent assessment by the U.S. National Academy of Sciences offers a comprehensive look at how climate change will affect this region and its water security.

The recent report on climate change and the Himalayan region from the U.S. National Academy of Sciences.

Even with climate change, the HKH region will have glaciers for centuries, but as temperatures rise, the lower elevation glaciers and snow will (and are beginning to) melt, recede, and disappear. In the eastern and central Himalayas, there is evidence that glacial retreat has accelerated over the past century. Black carbon and dust from burning of fossil fuels and wood are also accelerating this effect by darkening snow and ice and absorbing more energy from the sun.

The total amount of water in the rivers downstream may not change much – total flow will depend on how much precipitation overall (rain and snow) falls, especially during the rainy/monsoon seasons. But the timing of those flows is especially vulnerable to climate change – as it is in the western mountains of the United States, including the Rockies and Sierra Nevada. For river flows that are dependent on melting snow and ice, such as the rivers in the eastern Himalayas, the earliest climate change impacts are likely to be changes in the seasonality of flows, with increases in winter flows (as more precipitation falls as rain instead of snow, and as existing ice and snow melt faster) and then decreases in summer flows.

Because of the physical and climatological complexity of this huge region, the ultimate impacts of climate changes are complex and still incompletely understood. More basic science is needed – for example, even estimates of the total area of glaciers in the HKH region vary by almost a factor of two. But not everything is equally uncertain (a point often lost, by the way, on those who prefer to emphasize what we don’t know over what we do know).

The eastern Himalayas and the Tibetan Plateau are already warming, especially at higher elevations. Glacial retreat, especially in the central and eastern Himalayas, is already occurring and likely to accelerate. Lower elevation glaciers are disappearing faster than higher (and colder) ones. Black carbon and soot are contributing to faster ice melt. In the near term, some rivers may see increases in flow as ice melt grows. In the longer run, most regional rivers are likely to see changes in the timing of flows, with a concomitant change in flood and drought risks. And rising temperatures are also likely to increase evapotranspiration rates over large parts of the irrigated areas of the region’s major river basins, increasing total demand for water in places where demands already exceed supply in many part of the year and where food production is critical. These are the regions likely to be on the front line of any challenges to water resources from climate change.

Closer to home (for those readers in the western hemisphere), keep a close eye on the water towers of our own water supplies: the Rocky Mountains, the Sierra Nevada, and the Alps. Expect to see rising snowlines. Expect growing winter flows and flood risks as snow turns to rain and decreasing summer flows as the snow disappears earlier and earlier in the year. Expect to see our own (much smaller) glaciers shrink and disappear, as is already happening in Glacier National Park. [In a straight-faced comment on the Glacier National Park website, the National Park Service states:

“Despite the recession of current glaciers, the park's name will not change when the glaciers are gone.”

Maybe that’s fitting: disappearing or no glaciers in Glacier National Park will be a mark of our failure to act.

In the end, significant climate changes will occur because we’ve taken too long to acknowledge and react to the problem. And that means unavoidable impacts for water resources (and other things), and inevitable adaptation and reaction. But planning and acting now can still reduce the worst consequences later. There are plenty of things we can do, including improved water-use efficiency, better planning for floods and droughts, more sophisticated reservoir operations, and stronger institutions to manage water and reduce water conflicts. More on these options later.

Peter Gleick

pgleick Wed, 02/20/2013 - 05:28

We're So Lucky

sastyk — Fri, 09 Sep 2011 07:16:41 +0000

We're So Lucky

The first thing you need to know is that no one ever complains. I've seen a few people cry, mostly about lost pets, but what they say is "we're so lucky."

They say "We're so lucky" as elders in their 80s and 90s put all the possessions of a lifetime out on the street to be hauled away as trash. One couple told me "We're so lucky - we saved our wedding album and one picture of all the grandchildren together." There wasn't time for more before they evacuated. "We're so lucky - the kids lost all their toys, but we're staying with friends who have girls the same size as mine, so they have clothes and things..."

They say "We're so lucky" as they contemplate the loss of their livelihoods. A friend told me "I was so lucky, we had stock up on the high shelves that didn't get touched, and I was able to get that over to the shelter and start feeding people right away." She lost her whole business.

They say "We are so lucky" as they look at their fields washed away. "We are so lucky...we saved our buildings at least, even though we lost our whole crop." "We are so lucky, we lost our buildings, but we got the stock out and the tractors." "We are so lucky, we lost everything, but we're all safe." None of them know yet how much help will be forthcoming or when.

They say "We're so lucky" despite the loss of beloved animals and livestock. "We're so lucky, we got the milk cows out, and three of the heifers" they say - even though they lost all the year's calves and the rest of the heifers and spent two days trapped in their hayloft.

They say "we're so lucky" when they have to evacuate again - after they cleaned up and dried off, when Irene seemed to be over, and then Lee sent the rivers rising again. "At least we're safe, at least we have friends to go to."

Everyone knows someone who has it worse. No one is lying when they say "We are so lucky." That's the part that's hard to believe - even the second time around, when those who evacuated the first time are weary and back in the shelters, when those who dodged the bullet last time now know that everything may be washed away, they say - and truly mean - "We're so lucky."

They smile when they say it. They make jokes - a friend who has no money to mend her basement which had two of her sons' bedrooms in it told me "At least we had already ripped the carpet out from the last time!" Another friend said "I'm getting to kind of like the smell of the mold treater." And always, they are lucky - and they know it. Every single person knows that it could have been worse, that there could have been less help, that there could have been worse outcomes.

Over the weeks and months and years that follow as people try to reclaim their lives, there will undoubtedly be moments in which people do not feel lucky. And yet I don't think that invalidates the universal courage and kindness, stoicism and honest recognition that they are fortunate that shine out of my neighbors and through my community. Looking to them now, I cannot but know that we are so lucky to have them.

Sharon

sastyk Fri, 09/09/2011 - 03:16

Tags

That individuals can find the strength and grace to make statements like these may well be the candle that lights the darkness the future may (will) bring.

Sharon, could you make some suggestions about which organizations are responding to this disaster? I can find the good old Red Cross on my own, but I'd like my donation to find its way to those who are most immediately involved. Thanks.

What "withheld" said. I was born in Binghamton, now known as Atlantis, and lived in semi-rural central New York for my first 30 years, so I definitely want to do something to help the folks "back home."

We said the same thing after Katrina. And it was very true, we were so very lucky. But what I heard from many people where we evacuated to was that it was somehow our fault, that the victims were to blame, implying that something so bad could ever happen to them. This is the ugly side of disasters. People oftem blame the victims because that removes responsibility for caring or worrying that something similar could happen to you. I know this crowd isn't like that but I thought it was worth sharing.

Wonderful. Instead of getting mad and taking the government to task for global warming and an increase in these storms, the sheeple walk around bleating about being so lucky.

Pretty soon this will be a normal weather pattern for them and they can all join hands and sing while steadfastly thinking how lucky they are that the government takes care of them.

BAAAAAAAAaaaaaah

Sharon - this brought tears to my eyes. Please let us know if there's a way to help - like what "withheld" said.

And K demonstrates that even people who should be greatful for for what they have, and are untouched by this disaster, can still be an amazing whinebag.

Wonderfull post Sharon. It seems when push comes to shove most people just inherently understand what's most important and fall back on the hope for better day's. I'll be keeping your neighboors and other in the East in my prayers.

Beautiful. Thankfulness is indeed the attitude to have, and caring for one another the way to live (and antidote to self-pity.) Do let us know best means to assist.

a transplant from the East

K: this is a good weekend to remember that you learn a lot about people when shit happens. There are really three kinds: those who run away, those who freeze up, and those who run towards it to see what they can do.

And I'll add a vote for what "withheld" asked. I have family in the Delta country (and a sister-in-law from a Ninth Ward family) so Katrina was easy. Not hearing so much about New England. I know a little about how much disaster relief comes out of NE when there are fires, earthquakes, tornadoes, hurricanes, etc. around the world.

Don't hog the mitzvot, Sharon.

I think you have a handle here on a little studied aspect of why and how some H. sapiens are survivors. I think it needs more examination, understanding- and, well, just "more."

I have my own parallels to add; and they're really pretty astonishing. My farm got hit by a tornado this past summer. Real one. And we do find our selves saying and honestly feeling; "we're so lucky". It snapped off full grown oaks, 20 feet up, right next to our water pumping windmill. But the windmill was untouched. Etc.

Last week an old dear friend dropped in, as he does unannounced, twice a year. After two hours of talk, he dropped the bomb; "Two months ago I was diagnosed with leukemia."

Shock and horror. "No, I'm lucky, " he said; "it's the good kind." meaning, fairly treatable.

I'm still coping with the "lucky to have leukemia" outlook; but it's undeniably real.

Important, I think. More study is needed. Get a grant. :-)

Or put it in your book.

Just in case it wasn't clear- I am once again deeply impressed with your intelligence and humanity- in the way you put these observations together. You not only have a genius brain; you have a genius heart.

Plus that damn 6' Energizer Bunny body that does 4 times the work any of the rest of us manage.

:-p
:-)

As rain moves north, Galapagos could be left high and dry

sciencepunk — Sun, 05 Jul 2009 06:55:39 +0000

As rain moves north, Galapagos could be left high and dry

According to a press release from the University of Washington, tropical islands may become deserts as the climate band delivering their only supply of fresh water creeps north:

The rain band near the equator that determines the supply of freshwater to nearly a billion people throughout the tropics and subtropics has been creeping north for more than 300 years, probably because of a warmer world, according to research published in the July issue of Nature Geoscience.

If the band continues to migrate at just less than a mile (1.4 kilometers) a year, which is the average for all the years it has been moving north, then some Pacific islands near the equator - even those that currently enjoy abundant rainfall - may be drier within decades and starved of freshwater by midcentury or sooner. The prospect of additional warming because of greenhouse gases means that situation could happen even sooner.

Lead author Julian Sachs, associate professor of oceanography at the University of Washington, said:

We're talking about the most prominent rainfall feature on the planet, one that many people depend on as the source of their freshwater because there is no groundwater to speak of where they live. In addition many other people who live in the tropics but farther afield from the Pacific could be affected because this band of rain shapes atmospheric circulation patterns throughout the world.

The researchers found evidence of salt-tolerant microbes buried in lake sediments, corresponding to a period 400 - 1,000 years ago, suggesting a period of reduced rainfall. Additional evidence was provided by ratios of hydrogen isotopes of material in the sediments that can only be explained by large changes in precipitation. The findings are based on sediment cores from lakes and lagoons on Palau, Washington, Christmas and Galapagos islands.

sciencepunk Sun, 07/05/2009 - 02:55