Does global warming really reduce water availability on planet earth?

Question

http://news.yahoo.com/s/nm/20070912/ts_nm/climate_security_dc;_ylt=AguPlEfHfVcobAy9UG53hleOe8UF

My take is this is hype! I dont see how warming the earth and the resultant increase in water vapor/cloud formation reduces water availability. It may be redistributed but the failing crops etc is mostly hype.

Answer 1

Dana and Trevor are simply wrong in my opinion. More water vapor in the air is not going to come at the expense of groundwater. It might come at the expense of tiny bit of ocean, lake or river. Increased temperatures will indeed result in the atmosphere holding more water and it may result in increase evaporation and precipitation. The truth is noone knows the exact consequences and those that pretend to know like Dana and Trevor invariably see tragedy in everything. They pretend to be objective, yet they only see the glass as half empty and ignore the benefits. The benefits of GW on crops will be at least two fold. Increased temperatures will increase yeilds and growing seasons. Increase CO2 acts as a fertilizer and also reduces the amount of water that a plant needs. Not only was that article hype, it is idiotic and I'm not going to even qualify that with a "in my opinion".

Answer 2

You're pretty much on the right lines - the water is redistributed rather than reduced.

There will be a slight reduction in the amount of ground water due to a warmer atmosphere retaining more water vapour but this is more than offset by the additional resources provided by melting glaciers, snow caps, ice caps, ice sheets etc.

Warmner weather leads to increased evapouration from the seas and oceans and consequently increased precipitation. We've been seeing this for some time now. However, it's not as simple as more rain = more water.

One major problem is that for over a billion people their water supply comes from the melting of snow and ice (largely in Asia). Already many glacier fed rivers have dried up and the people downstream no longer have a water supply, this problem is getting worse - more and more rivers and lakes are drying up and almost every glacier and snow cap on the planet is retreating.

The rainfall isn't consistent, weather dynamics are complicated but in short it means that some places receive more rain and others receive less, even though the global rainfall has increased. The places to receive less are by and large those that already have an intermittent or low rainfall - the ones least able to cope with reduced rainfall.

Failing crops is very much a reality, something I went out to Africa and examined for myself last year. In an area that would normally have been served by 7 or 8 wells one by one they'd dried up over the last 10 to 15 years and the only remaining well in an area of 1000 square miles was at the local school.

In some areas crops do better due to increased / decreased rainfall and / or warmer temps but overall crop yields fall as global temps rise. There has been a 10% reduction in global crop yields, a figure that's rising. For us in the developed world it's no big deal as it just means a loaf of bread costs a bit more. For those who rely on subsistence farming or local agriculture the effects can be devastating.

Answer 3

Failing crops have been a reality since the beginning of agriculture and has always been primarily due to the unpredictability of weather/water supply and poor management. As advanced and experienced as we have become over the centuries, those problems still exist and will continue to exist. It's entirely disingenuous to attribute this to global warming. Or to suggest that somehow we will have less freshwater.

It's funny how alarmists insist that water cannot be a forcing because it precipitates out too quickly, but then totally disregard that when temperature increases, the absolute humidity also increases - essentially locking up water in the atmosphere. It is a greenhouse potential that is disregarded as merely a "feedback", as if the word has any real meaning in respect to the greenhouse effect (ie - the greenhouse effect is a feedback effect since it produces no heat on its own.)

Answer 4

I work with river systems and as far as i'm concerned, I don't think availability of water is going to be an issue. It will be water quality. The water cycle is such a large system ( the oceans acting as buffers ) that good old H2O isn't dissappearing, but the quality of rainfall over landmass, and pollution within the water table, could affect crop production. Advances in technology and filtration systems will also mean that de-salination plants could become cost effective, and hence any country with a coastline has access to water.

Answer 5

More accurately, it reduces freshwater availability on the planet Earth, but the answer is yes.

It's pretty simple when you think about it. Take California for example. A lot of our water comes from the melting snowpack in the Sierra Nevadas. If the climate is warmer and less snow falls, there's less to melt and less freshwater available.

I don't understand your logic that if water is redistributed then crops won't fail. If a location is used to having plentiful water and suddenly rainfall decreases, the crops will fail. If another location is hit by floods, crops will fail. Some of the effects of global warming are that you see increased droughts, heat waves, and floods.

Sorry, but the predictions made by this article/study are accurate. Climate scientists have been predicting this sort of thing for quite a while now.

*edit* jim, this is not my opinion (unlike your answer, which as you admit, is just your opinion). My answer is based on the research of climate scientists who agree about these consequences of global warming.

Answer 6

Your answer is complicated by way of fact it incredibly is not all one element. in case you settle for the argument for guy-led to international warming, the easy answer is "no." there have been no proposals that could replace something different than the time line of the upward thrust in atmospheric CO2. the end result may be moved into the destiny somewhat some quantities, yet not adequate to make a distinction to ecosystems. international warming isn't the reason for arctic melting, yet extremely it incredibly is led to by capacity of the climate phenomenon commonplace by way of fact the Arctic Oscillation. This climate trend changes with the comparable styles of whims climate types in many circumstances do - there's no commonplace correlation with atmospheric CO2 replace. whilst it incredibly is interior the warmth area, which it incredibly is been for the previous couple of many years, it brings heat air from the Pacific over the Arctic and pushes the Arctic air down into the North Atlantic. it incredibly is an incredibly localized phenomenon. i grew to become into in Fairbanks 2 years in the past and observed the permafrost factors have been nevertheless the place the handbook (a Fairbanks close by) indicated that they were all her existence. whilst the Arctic Oscillation switches the Arctic will refreeze.

Answer 7

More Water Vapor means more Rain.
More rain means more fresh water.
Simple...

edit:
Jim you are right on theory but Global warming does not "cause" an increase in CO2.

Answer 8

Ask the people in Darfur. This is just like the food situation. The supply has been outgrown. These type things can't be considered just distribution problems anymore.

Answer 9

They ascribe to a total chaos theory. As Algore once said when he was running for VP "Every thing that's supposed to be up is down and every thing that is supposed to be down is up" So despite global glacier melting,searise and flooding somebody is gonna be outa water somewhere no matter what.

Answer 10

i guess its something to think about. i mean theres many things going for it and against it, but from what i have read it is happening n the proof that they have is a lake in africa that is dissapearing. they show how it looked back then (10 or 20 years ago) n now.