climate impacts
pgleick | December 4, 2013Just to provide a little perspective, here are the latest data and a graph on atmospheric carbon dioxide, with information going back 800,000 years. Present day is on the far right ("You are here"). The data come from the atmospheric monitoring program of the Scripps Institution of Oceanography, La Jolla, California and can be found here.
I've also noted the approximate period when homo sapiens first appeared -- thought to be around 150,000 to 200,000 years ago. During all human existence, pre-industrial levels of CO2 never exceeded around 275 parts per million (ppm). They touched 400 ppm…
illconsidered | November 12, 2013While reading an AP attributed article on Huffington post about Super Typhoon Haiyan (also known as Yolanda), I did a double take at this paragraph:
Weather officials said Haiyan had sustained winds of 235 kilometers per hour (147 miles per hour), with gusts of 275 kph (170 mph), when it made landfall. By those measurements, Haiyan would be comparable to a strong Category 4 hurricane in the U.S., and nearly in the top category, a 5. Hurricanes, cyclones and typhoons are the same thing. They are just called different names in different parts of the world.
It struck me because "nearly in the…
pgleick | October 14, 2013Snow. Glaciers. Icecaps, River flows. All of these are vulnerable to climate change, especially rising temperature. This isn't just theory. It’s now observable fact.
Scientists worry about the growing threat of climate change because the global climate is tied to everything that society cares about: human and environmental health, food and industrial production, water availability, extreme events, and more. Figuring out how all these pieces tie together is difficult. And many of us, from scientists to the public to policy makers, have only a partial understanding of the true implications of…
pgleick | September 27, 2013The latest in a long series of science summaries on climate change from the Intergovernmental Panel on Climate Change (IPCC) has just been released. While the report has a massive amount of information in it, related to a wide range of geophysical implications of climate change, here are some of the key water-related findings for precipitation, evaporation, glaciers, ice mass, and more. While many other findings are reported that have hydrologic implications (such as all the findings related to temperature and warming), I have not usually included them here. Definitions of the confidence of…
pgleick | August 19, 2013
Dropping water levels in Lake Mead, behind Hoover Dam. (Source: Peter Gleick 2013)
It is no surprise, of course, that the western United States is dry. The entire history of the West can be told (and has been, in great books like Cadillac Desert [Reisner] and Rivers of Empire [Worster] and The Great Thirst [Hundley]) in large part through the story of the hydrology of the West, the role of the federal and state governments in developing water infrastructure, the evidence of droughts and floods on the land, and the politics of water allocations and use.
But the story of water in the West…
pgleick | July 16, 2013
The evidence from real-world observations, sophisticated computer models, and research in hundreds of different fields continues to pile up: human-caused climate change is already occurring and will continue to get worse and worse as greenhouse-gas concentrations continue to rise.
Because the climate is connected to every major geophysical, chemical, and biological system on the planet, it should not be surprising that we are learning more and more about the potential implications of these changes for a remarkably wide range of things. And while it is certainly possible – even likely – that…
pgleick | June 10, 2013There is a long history of conflicts over water – the Pacific Institute maintains an online, searchable chronology of such conflicts going back 5,000 years. There were dozens of new examples in 2012, in countries from Latin America to Africa to Asia. (A full update for 2012 has been posted.) Access to water and the control of water systems have been causes of conflict, weapons have been used during conflicts, and water systems have been the targets of conflict.
One especially disturbing example of a major conflict, with complicated but direct connections to water, has developed over the past…
pgleick | June 6, 2013One day, sometime around the middle of this century, during the lifetime of people now alive, the population of the planet will be smaller than it was the day before. Global population growth is slowing, will level off, and one remarkable day, decline.
This day will mark the dividing line – the definitive transition – between a world dominated by the concept of exponential, inexorable growth to one that has the opportunity to come to grips with true long-term global sustainability.
Ever since the dawn of humanity, the population of the planet has been growing (ok, some quibblers may point out…
pgleick | May 10, 2013The planet has passed a disturbing landmark, a marker on a continuing highway to climate disruption. On May 9th, the NOAA and the Mauna Loa observatory reported that atmospheric CO2 levels touched 400 parts per million. Before humans started burning fossil fuels, they were around 280 parts per million.
Mauna Loa measurements of carbon dioxide. From http://keelingcurve.ucsd.edu/
The last time atmospheric CO2 was at 400 parts per million was during the ancient Pliocene Era, three to five million years ago, and humans didn’t exist.
Global average temperatures were 3 to 4 degrees C warmer…
pgleick | May 10, 2013The Colorado River, recently named America’s most endangered river, supports millions of people in the American Southwest and northwest Mexico and helps irrigate millions of acres of land. It is shared by seven states in the U.S. and Mexico, through a complex series of legal agreements and treaties.
Yet every drop of water on the river is accounted for, used, reused, and transpired away, and today, no water reaches the Colorado River delta in an average year. Quite simply, demands on the river exceed the river’s average supply, and this problem is projected to get worse as populations…
pgleick | April 10, 2013On April 2nd, I posted three iconic graphs showing some of the clear observational evidence that we’re changing the climate. That post produced a substantial, and largely thoughtful response, and a request for more information and data along these lines.
Here are three more, along with a bonus fourth, all with a theme of exponential growth – the powerful force that is behind much of the concern about climate change and many other environmental and social challenges. Figures like these are increasingly called “hockey stick” curves, after the work of Professor Michael Mann and others in the…
pgleick | April 2, 2013Here are three iconic graphs (unfortunately, there are many, many more) showing just some of the clear observational evidence that we're changing the climate.
The first is the atmospheric concentration of carbon dioxide, measured at the Mauna Loa observatory in Hawaii. It shows the little ups and downs in concentration that varies with the seasons, but also the inexorable rise in this powerful greenhouse gas. There are now thousands of stations measuring these gases.
The second is the deviation from global average temperatures over the past 130 years. It also shows the natural variability (…
pgleick | March 21, 2013Some thoughts for today: the bad news and good news for World Water Day. [First, I think every day should be World Water Day, not just March 22nd, but hey, that’s just me.]
Stop taking your tap water for granted. Go to your tap, draw a glass of water, and drink it. Then remember that nearly a billion people still do not have reliable access to safe, affordable tap water and cannot do what you've just done.
Stop taking your toilet for granted. Nearly 2.5 billion people (more people than lived on the planet in the 1930s) don’t have safe sanitation.
Do you know anyone who had cholera, or typhoid…
pgleick | March 21, 2013Nearly two years ago, Science magazine published the following Lead Letter, signed by 255 members of the U.S. National Academy of Sciences addressing attacks on the integrity of climate science. The science has continued to strengthen, the evidence in real world observations has become even stronger and more obvious.
In response, in the past few months, there has been a last-gasp effort (see, for example, here and here) on the part of the ever-shrinking group of hard-core climate deniers to confuse the public and especially our elected officials. Given this continuing profusion of false and…
pgleick | March 7, 2013Sometime, about one year from now, the front pages of whatever decent newspapers are left will carry a headline like the one above, announcing that for the first time in human existence (or in nearly a million years, or 3 million years, or 15 million years), the global atmospheric concentration of carbon dioxide – the principal gas causing climate change – will have passed 400 parts per million.
That’s a significant and shocking figure. Unfortunately, it is only a temporary marker on the way to even higher and higher levels. Here (Figure 1 below) are the most recent (March 2013) data from the…
pgleick | February 26, 2013One of the most important and threatening risks of climate change is sea-level rise (SLR). The mechanisms are well understood, and the direction of changes in sea-level is highly certain – it is rising and the rate of rise will accelerate. There remain plenty of uncertainties (i.e., a range of possible outcomes) about the timing and rate of rise that have to do with how fast we continue to put greenhouse gases in the atmosphere, the responses of (especially) ice sheets in Greenland and Antarctica, and the sensitivity of the climate.
Even little changes can have big consequences. As we saw…
pgleick | February 20, 2013One 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…