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Eau (régime, cycle...)

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Si précieuse et si liée au climat.

WaterCycle. Une rivière entière a disparu au Canada en à peine quatre jours. Scientists say that human-caused climate change rerouted a river. For years, oil and gas companies have plumbed the earth beneath Los Angeles.

Scientists say that human-caused climate change rerouted a river.

And in most cases the companies and city — surprise! — allegedly sidestepped environmental laws in the process. Poor communities of color have suffered the most. “The city disproportionately exposed people of color to greater health and safety impacts,” says attorney Gladys Limón of the environmental justice nonprofit Communities for a Better Environment. In 2015, the Center for Biological Diversity and two local youth groups, Youth for Environmental Justice (which is affiliated with CBE) and the South Central Youth Leadership Coalition, sued L.A. The city settled out of court in September 2016. Houston flooding is a perfect storm of climate change and bad urban planning. Flooding in Texas killed six over Memorial Day weekend, bringing the death toll from the state’s unprecedented floods this year to at least 14.

Houston flooding is a perfect storm of climate change and bad urban planning

The area surrounding Houston has been hit especially hard: On Sunday, about 2,600 inmates were evacuated from two southeastern Texas prisons endangered by high water, and evacuation orders were issued Monday for homes along the Brazos River. Deluges like this aren’t exactly new to the area — downpours at this time last year brought a death toll of at least 30 — but as the climate warms, so does risk of flooding. In the past 30 years, reports the AP, the frequency of extreme downpours in the area has doubled. “One likely cause,” Texas’ state climatologist John Nielsen-Gammon tells Grist, “is the increase in ocean temperatures from the Gulf of Mexico and tropical Atlantic. Climate change is sucking the Colorado River dry. Even as the number of Americans relying on the Colorado River for household water swells to about 40 million, global warming appears to be taking a chunk out of the flows that feed their reservoirs.

Climate change is sucking the Colorado River dry

Winter storms over the Rocky Mountains provide much of the water that courses down the heavily tapped waterway, which spills through deep gorges of the Southwest and into Mexico. But flows in recent decades have been lighter than would have been expected given annual rain and snowfall rates — and a new study has pinpointed rising temperatures as the likely culprit. “For a given precipitation over the cool season, from October through April, we’re seeing less flow than we’ve seen in the past,” said James Prairie, a researcher with the U.S. Bureau of Reclamation’s Upper Colorado Regional Office. He was not involved with the new study. The new research, published in Geophysical Research Letters by academics and a federal scientist, focused on the upper stretches of the river.

Scientists have found “God’s bathtub,” a lake totally untouched by climate change. Le lac Poopó, deuxième plus grand lac de Bolivie, a complètement disparu. Considéré comme le deuxième plus grand lac de Bolivie, le lac Poopó situé dans les hauteurs de l’Ouest du pays est aujourd’hui complètement à sec.

Le lac Poopó, deuxième plus grand lac de Bolivie, a complètement disparu

En cause : l'absence de précipitations et la négligence des exploitations minières environnantes. A le voir aujourd’hui, il semble difficile de croire que le lac Poopó, situé dans les hauteurs de l’Ouest de la Bolivie, a été un temps la deuxième plus grande étendue d’eau du pays, après le lac Titicaca. Ce qui lui est arrivé est un véritable désastre. Victime du changement climatique et de diverses négligences industrielles, ce lac salin a complètement disparu en décembre 2015, laissant dernière lui une vaste surface désertifiée d’environ 4.000 kilomètres carrés.

Could flooding finally wake Americans up to the climate crisis? One of the perennial discussions in climate circles is about which impacts will break through the noise and apathy to finally galvanize people to do something about the problem.

Could flooding finally wake Americans up to the climate crisis?

The usual suspects are droughts and food shortages, since they’re expected to bite first. My own dark-horse candidate has been sea level rise. As I wrote last year, the carbon in the atmosphere today has already “locked in” enough sea level rise to swamp hundreds of coastal cities and towns around the world. Some 316 settlements in the lower 48 states, with a cumulative 3.6 million residents, are already doomed.

If we continue on our current trajectory, 1,400 American towns and cities will eventually, inevitably be lost to the ocean. But when? But! Rather than focus on average sea level, researchers focused on the frequency of “nuisance-level” flooding events, defined as water one or two feet higher than local high-tide level. Second, lots of American cities and towns are on the verge of serious trouble. This was an epic year for droughts, floods, and extreme weather. Stick your hand over a lit stove and you can get a feel for 2014’s overall climatic situation: scorching heat.

This was an epic year for droughts, floods, and extreme weather

For months, experts have been predicting this will be the hottest year in recorded history, and while in the end it might not quite achieve that ignoble record, it will be way up there (perhaps at No. 3). The thermostat could’ve seemed low in your neck of the woods — meaning America’s East Coast and Midwest and the Falkland Islands — but temperatures were sweltering in the rest of the planet. Take a look at these abnormally high and record-hot readings, which represent a 1.2 degrees Fahrenheit deviation above the historical average. Notes the National Climatic Data Center: “This was the warmest January-November in the 1880-2014 record, surpassing the previous record set in 2010 by 0.02 degrees F.” Réchauffement : le sud-est de la France face à une crise de l'eau. Le Monde.fr | • Mis à jour le | Par Richard Schittly (Lyon, correspondant) Un climat à Lyon équivalent à celui d'Avignon il y a trente ans, une diminution d'un mois d'enneigement sur les Alpes, une baisse des débits d'étiage, une plus forte évaporation, 40% des territoires de Rhône-Méditerranée souffrent désormais de pénurie chronique en eau.

Réchauffement : le sud-est de la France face à une crise de l'eau

Le quart sud-est de la France connaît déjà les répercussions du changement climatique sur les ressources hydriques et doit se mobiliser immédiatement. Dans un rapport intitulé « plan de bassin d'adaptation au changement climatique dans le domaine de l'eau », le comité de bassin Rhône-Méditerranée tire la sonnette d'alarme. Réchauffement climatique : votre région va-t-elle manquer d'eau? Certes, rarement la pluie se sera autant déversée sur notre pays, qui reçoit déjà, en tant normal, 480 millions de mètres cubes d'eau venant du ciel !

Réchauffement climatique : votre région va-t-elle manquer d'eau?

Mais, à terme, et du fait du réchauffement climatique, la situation pourrait s'inverser. Et une grande inégalité des régions françaises devant les ressources en eau se profile à l'horizon 2030, indique mercredi 3 avril un rapport du Centre d'analyse stratégique (CAS) qui pointe le Sud-Ouest et les bassins Seine-Normandie et Rhône-Méditerranée comme des territoires à risque, dans le contexte de réchauffement climatique.

Si le CAS note que "le territoire métropolitain français est globalement bien pourvu en ressources en eau", il existe de "très fortes disparités", ce qui explique qu'aujourd'hui "certaines régions peuvent connaître d'importantes tensions sur la ressource à certaines périodes de l'année". Le rapport inscrit les futurs besoins dans un contexte marqué par le réchauffement climatique. Même le débit du Rhône est menacé (Avec AFP)