Explaining climate change science & rebutting global warming misinformation
Scientific skepticism is healthy. Scientists should always challenge themselves to improve their understanding. Yet this isn't what happens with climate change denial. Skeptics vigorously criticise any evidence that supports man-made global warming and yet embrace any argument, op-ed, blog or study that purports to refute global warming. This website gets skeptical about global warming skepticism. Do their arguments have any scientific basis? What does the peer reviewed scientific literature say?
Posted on 22 August 2014 by Guest Author
Climate scientists have long tried to explain why ice-age cycles became longer and more intense some 900,000 years ago, switching from 41,000-year cycles to 100,000-year cycles.
In a paper published this week in the journal Science Express, researchers report that the deep ocean currents that move heat around the globe stalled or may have stopped at that time, possibly due to expanding ice cover in the Northern Hemisphere.
"The research is a breakthrough in understanding a major change in the rhythm of Earth's climate, and shows that the ocean played a central role," says Candace Major, program director in the National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research.
The slowing currents increased carbon dioxide (CO2) storage in the oceans, leaving less CO2 in the atmosphere. That kept temperatures cold and kicked the climate system into a new phase of colder, but less frequent, ice ages, the scientists believe.
"The oceans started storing more carbon dioxide for a longer period of time," says Leopoldo Pena, the paper's lead author and a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory (LDEO). "Our evidence shows that the oceans played a major role in slowing the pace of the ice ages and making them more severe."
Posted on 21 August 2014 by John Abraham
Meteorologists have the tools to clearly understand how humans are affecting the Earth’s climate. For folks who study weather every day, the changes they’ve seen defy natural explanation. But most meteorologists have to balance their very limited airtime and their reporting obligations with a desire to convey the reality of climate change.
It’s very rare that a meteorologist, let alone a major media organization, take time to bring in-depth discussions to their listeners. But, just this has happened approximately a year ago at Minnesota Public Radio, the largest public radio enterprise in the United States with their star meteorologist Paul Huttner and his deeply knowledgeable host Kerri Miller. This unique venture (a weekly climate show CLIMATE CAST and a weather and climate blog UPDRAFT) and talented team is setting the standard for climate reporting in the United States.
In barely a year, their guest list has included Kevin Trenberth, Ben Santer, Jennifer Francis, Gary Yohe, Anthony Leiserowitz, Steve Vavrus, and Ralph Keeling among others. The depth and reach of Climate Cast have motivated my selection of Paul as my latest Scientist in Focus.
As with most of us, Paul can trace his climate trajectory to his lived experiences. Almost 20 years ago, he covered the infamous Chicago heat wave. That event, which killed approximately 750 citizens, opened his eyes to the impacts of extreme weather events.
Posted on 20 August 2014 by John Hartz
- A ‘major challenge’ to South Asia’s economic development
- Cities’ air problems only get worse with climate change
- Climate change reflected in altered Missouri River flow
- Climate scientist calls on colleagues to speak up on global warming
- Defending forests is daily life for Indian woman leader
- Deforested idle land identified as source of Indonesia "haze" fires
- Earth sliding into ‘ecological debt’ earlier and earlier
- Greenland ice loss doubles from late 2000s
- Here’s how Arctic sea ice could shrink even more
- July checks in as 4th warmest on record worldwide
- Scientists warn of dangers from ocean acidification
- Towards a new co-existence: On reframing our ecological crises
- UN climate talks on path to fall far short of goals
- Understand faulty thinking to tackle climate change
- What I learned from debating science with trolls
A ‘major challenge’ to South Asia’s economic development
India, Sri Lanka, Bangladesh, Bhutan, the Maldives and Nepal will face "major challenges" as the impacts of climate change start to bite, according to a new report.
The Asian Development Bank's (ADB) 163-page analysis outlines how warmer temperatures and rising seas could hit South Asia's varied economies, home to nearly 1.5 billion people.
It concludes that the "impacts of climate change are likely to result in huge economic, social and environmental damage to South Asian countries".
Climate change a ‘major challenge’ to South Asia’s economic development, report claims by Mat Hope, The Carbon Brief, Aug 20, 2014
Posted on 20 August 2014 by robert way
In 1534, famed explorer Jacques Cartier described Labrador as "the land God gave to Cain". This comparison is inevitably linked to Labrador’s rugged coastal landscapes dotted with deep inlets, fiords and rugged tundra. Culturally the region is steeped in complexity with three distinct indigenous populations intertwined with settlers and settler descendants.
In the north lies the Inuit settlement area of Nunatsiavut, where its predominantly Inuit residents are spread across 5 small communities. The Torngat Mountains National Park is located on the northern tip of Nunatsiavut where the tundra landscape forms part of the Arctic Cordillera and sustains small mountain glaciers along the coast (Brown et al, 2012; Way et al. Accepted). The Arctic treeline in the area descends as low as ~57°N due to the prevailing influence of cold polar water transported along the Labrador coastline by the Labrador Current.
In central and western Labrador, where the climate is considered subarctic, the indigenous population has historically been members of the Innu Nation who every year traveled north to George River to hunt the George River Caribou herd. Currently, there are two Innu communities (Natuashish and Sheshatshiu) which have a combined population of ~2,000 residents. The third aboriginal group in Labrador is largely made up of Inuit who have intermixed with the early European settlers and are now referred to as Nunatukavut (formerly Métis). Their traditional activities span the lands from Cartwright south along the Labrador coast where boreal forest meets coastal barrens.
Throughout much of the modern era of global warming (post-1950s) air and ground temperatures in Labrador cooled, contrasting with many other regions (Allard et al. 1995; Banfield and Jacobs, 1998). This cooling continued until the late 1990s when regional air temperatures begin to warm rapidly (Brown et al. 2012; Way and Viau, In press; Figure 3).
In coastal Labrador, the human impacts of recent climate change have been ubiquitous for the Labrador Inuit who are reliant on sea ice and snow for accessing traditional hunting grounds and neighboring communities. These communities are only accessible by air and sea in the summer and air and snowmobile in the winter. Recent winter warming and local reductions in sea ice/snow cover have reduced access for Inuit to traditional fishing and hunting grounds and also neighboring communities (Wolf et al. 2013).
Vulnerability assessments have identified food security as being a key area in which Labrador’s coastal communities will be susceptible to climate change in the future, which is expected to be on the order of 3°C by 2038-2070 (Finnis 2013). However, the region’s geographic location makes it intrinsically linked to climate variability in the North Atlantic, complicating future climate projections (D’Arrigo et al. 2003).
Posted on 19 August 2014 by Dikran Marsupial
As September is rapidly approaching, I thought I would update my statistical prediction for this years September mean Arctic sea ice extent. I submitted the prediction in July to the Sea Ice Prediction Network, and it seems to be rather lower than the majority of the other predictions (as my prediction is listed as "Cawley"):
Last Year's Prediction
Before discussing this year's prediction, lets see how we fared last year. The prediction made last year is shown in Figure 2, and predicted a 2013 September Arctic sea ice extent of 4.1 ± 1.1 million square kilometres. The minimum Arctic sea ice extent of 5.10 million square kilometres was reached on September 13, 2013. Obviously this figure is substantially greater than the prediction, but still lies within the error bars of the projection, and so fits within the range of inter-annual variability considered plausible by the model. The September mean extent was 5.35 million square kilometres, which lies slightly above the credible interval. Note also that the model actually predicts the mean Arctic sea ice extent for the month of September, and so can be expected to somewhat over-estimate the September minimum.
Posted on 18 August 2014 by dana1981
As people’s understanding of climate science grows, among both experts and non-experts alike, we become more accepting of the fact that humans are the driving force behind global warming. That’s because the evidence supporting human-caused global warming is overwhelming; hence rejection of that reality is usually based on an incomplete understanding of the scientific evidence.
In Australia, Prime Minister Tony Abbott’s chief business adviser Maurice Newman offered a prime example of global warming denial last week. Writing in The Australian, Newman suggested that we’re headed for a period of global cooling due to declining solar activity and related influences from galactic cosmic rays, calling mainstream climate science “a religion.”
As Graham Readfearn showed in his fact check of The Australian opinion piece, Newman got the science badly wrong in almost every way imaginable. Scientific research has consistently shown that a grand solar minimum would barely make a dent in human-caused global warming, and that galactic cosmic rays do not exert a significant influence on the Earth’s climate. To argue otherwise, Newman relied on selective cherry picking of some research, and a misinterpretation of other studies.
Posted on 17 August 2014 by John Hartz
Global warming is moistening the atmosphere by John Abraham garnered the highest number of comments of the articles posted on SkS during the past week. Dana's New study finds fringe global warming contrarians get disproportionate media attention drew the second highest number of comments. Both articles are shortened versions of the what was published by each author on their shared blog post, Climate Consensus-the 97% hosted by The Guardian.
El Niño Watch
- Renewed signs of an El Nino event in 2014 by Peter Hannam, Sydney Morning Herald, Aug 12, 2014
- El Nino’s Delay Spurs Memories of 2012 When It Never Came by Brian K Sullivan, Bloomberg, Aug 15, 2014
Toon of the Week
h/t to I heart Climate Scientists
Posted on 17 August 2014 by John Hartz
- As Earth warms, relationship between science and religion thaws
- Climate change: the elephant in the room
- Climate change will widen the social and health gap
- Communicating climate change – without the scary monsters
- Corporate Australia in denial over climate change
- El Nino’s delay spurs memories of 2012 when it never came
- Is climate change key to the spread of Ebola?
- Many Republicans privately support action on climate
- Snowpack atop Arctic sea ice has dwindled since 1950s
- Solomons town to relocate to escape climate change, tsunamis
- Why we're definitely not headed for another Ice Age
- Will it be extinction or 'translocation' as impacts of climate change increase?
As Earth warms, relationship between science and religion thaws
Congregants in a Miami church handed the Rev. Mitch Hescox a Bible to take with him to Tallahassee. It was a gift for the governor, and it accompanied 60,000 signatures the reverend had collected, all from evangelical Christians, all asking Gov. Rick Scott to do more on climate change.
Hescox is a leader of a movement among conservative Christians to acknowledge climate change and push elected officials to do more to mitigate its damage.
He's hardly a wild-eyed environmentalist — a lifelong Republican, he considers himself a conservative on most issues. Nevertheless, Hescox represents a growing group of evangelicals who believe stewardship of the Earth is a believer's duty.
The reverend, who for the last five years has served as president of the Washington, D.C.-based Evangelical Environmental Network, brought his message to South Florida last week. This state is expected to be a crucial battleground in the fight against rising seas. At the same time, its governor has been famously climate-change averse.
As Earth warms, relationship between science and religion thaws by Dan Sweeney, Sun Sentinel, Aug 16, 2014
Posted on 16 August 2014 by John Hartz
- Adaptation gaps mean African farmers fork out more money for reduced harvests
- Antarctica may lift sea level faster in threat to megacities
- Charles Mann and The Atlantic miss the mark in a confused climate change piece
- Dismantling Australian climate policy: a case study in disagreement
- Heavy rain and floods: The 'new normal' with climate change?
- Montana: Big Sky country, big climate problems
- Recent glacial melt mostly caused by man-made greenhouse gas emissions
- Recent urban floods: A simple equation
- Swamped by rising seas, small islands seek a lifeline
- Thinning Arctic snow could alter North Pole ecosystem
- Tibet's glaciers at their warmest in 2,000 years - report
- Why are we not taking climate change seriously?
Adaptation gaps mean African farmers fork out more money for reduced harvests
In Cameroon’s Northwest Region, Judith Muma walks 9km from her home to her 300-square-metre farm. The vegetables she grows here are flourishing thanks to the money she has borrowed from her njangi (thrift group) and a local credit union to finance a small artisanal irrigation scheme.
“I spend more money today buying farm implements such as water tanks, watering pumps, fertilisers, insecticides and improved seeds. I think we must spend in farming today if we want to adapt to climate change,” Muma tells IPS.
Cameroon’s economy is primarily agrarian and about 70 percent of this Central African nation’s 21.7 million people are involved in farming. Changes in temperature and precipitation pose a serious threat to the nation’s economy where agriculture contributes about 45 percent to the annual GDP.
Adaptation Gaps Mean African Farmers Fork Out More Money for Reduced Harvests by Monde Kingsley Nfor, Inter Press Service (IPS), Aug 14, 2014
Posted on 15 August 2014 by Guest Author
This is a re-post from Roz Pidcock at Carbon Brief
Last month, forecasters were predicting with 90 per cent certainty we'd see an El Niño by the end of the year, driving severe weather patterns worldwide. But with little sign so far of the ocean and atmospheric changes scientists expected, those odds have dropped off quite a bit.
We'll probably still see an El Niño before the year's out but it's unlikely to be a strong one, scientists are saying.
What is an El Niño?
Every five years or so, a change in the winds causes a shift to warmer than normal ocean temperatures in the equatorial Pacific Ocean - a phenomena known as El Niño.
Together, El Niño and its cooler counterpart La Niña are known as the El Niño Southern Oscillation (ENSO). Between them, they're responsible for most of the fluctuations in global weather we see from one year to the next.
Posted on 14 August 2014 by John Hartz
- Ants may boost CO2 absorption enough to slow global warming
- Brazil readies big push on solar energy but companies are wary
- Climate change and health - joining the dots
- Cutting emissions to avoid the worst impacts of climate change
- Danger to Great Barrier Reef growing
- In the ocean, clues to change
- Keystone XL could be worse for climate change than U.S. claims
- 'Not a mystery' why Republicans are blind facts on climate change
- Renewed signs of an El Nino event in 2014
- Rules prevent solar panels in many states with abundant sunlight
- Scientific consensus on climate change has not permeated the public
- The lasting damage of sudden heat waves is highly unpredictable
- Tony Abbott under pressure to put climate change on G20 agenda
- What climate change in the Rockies means for its water
- Why more companies should tie bonuses to sustainability
Ants may boost CO2 absorption enough to slow global warming
What if you could build a brick fence in your backyard that would offset a portion of your daily carbon dioxide emissions, such as those produced on your drive home from work? Would you do it?
Ronald Dorn, professor of geography at Arizona State University in Tempe, would. Except the fence he has in mind wouldn’t be just constructed from any old brick. It would be coated with calcium or magnesium and inhabited by a colony of ants.
If this idea sounds bizarre to you, that’s probably because—as Dorn himself would admit—it is. Yet, he says, it is conceivable that people all over the world could one day use their own version of this mineral/ant–based method of CO2 capture to limit the gas in the atmosphere and thereby help control its global heating effects.
Ants May Boost CO2 Absorption Enough to Slow Global Warming by Kevin Schultz, Scientific American, Aug 12, 2014
Posted on 13 August 2014 by John Abraham
We have long suspected that greenhouse gases which cause the Earth to warm would lead to a wetter atmosphere. The latest research published by Eul-Seok Chung, Brian Soden, and colleagues provides new insight into what was thought to be an old problem. In doing so, they experimentally verified what climate models have been predicting. The models got it right… again.
To be clear, this paper does not prove that water vapor is a greenhouse gas. We have known that for years. Nevertheless, the paper make a very nice contribution. The authors show that the long-term increase in water vapor in the upper troposphere cannot have resulted from natural causes – it is clearly human caused. This conclusion is stated in the abstract,
Our analysis demonstrates that the upper-tropospheric moistening observed over the period 1979–2005 cannot be explained by natural causes and results principally from an anthropogenic warming of the climate. By attributing the observed increase directly to human activities, this study verifies the presence of the largest known feedback mechanism for amplifying anthropogenic climate change.
Posted on 12 August 2014 by dana1981
A new study led by Bart Verheggen surveyed 1,868 scientists studying various aspects of climate change, asking them several questions mainly focused on what’s causing global warming. They survey also asked the respondents,
How frequently have you featured in the media regarding your views on climate change?
The answers to this question reflect whether the media is really fair and balanced on the subject of global warming. A truly balanced media would give equally proportional attention and coverage to climate scientists in the mainstream and on the fringes. For example, if 20% of contrarian climate scientists reported frequent media attention, a fair and balanced media would also give frequent coverage to 20% of mainstream climate scientists.
Instead, fringe contrarian climate scientists reported that they receive frequent media coverage twice as often as mainstream climate scientists.
Posted on 11 August 2014 by Bart Verheggen
This is a repost from Bart Verheggen's blog.
1. What are the objectives of this survey?
The PBL aimed to characterize the spectrum of scientific opinion about physical climate science issues. The research was focused on issues that are a frequent topic of public debate, and explored questions such as:
- On which issues is there widespread agreement amongst scientists?
- On which issues do scientists hold varied opinions?
- How does the spectrum of scientific opinion compare to IPCC assessments?
- How do scientists view skeptical arguments and viewpoints?
2. What is the relevance of an opinion survey or of measurement of consensus in trying to assess the science?
Science is based on the critical evaluation of available evidence in the context of existing knowledge. It is not “just an opinion.” With this survey, we tried to identify how scientists assess the different viewpoints that exist in public discussions of climate science. If the evidence for a certain viewpoint has become sufficiently strong and stable over time, the scientists’ aggregated opinion could be expected to reflect that.
Posted on 11 August 2014 by Bart Verheggen
This is a repost from Bart Verheggen's blog.
- A survey among more than 1800 climate scientists confirms that there is widespread agreement that global warming is predominantly caused by human greenhouse gases.
- This consensus strengthens with increased expertise, as defined by the number of self-reported articles in the peer-reviewed literature.
- The main attribution statement in IPCC AR4 may lead to an underestimate of the greenhouse gas contribution to warming, because it implicitly includes the lesser known masking effect of cooling aerosols.
- Self-reported media exposure is higher for those who are skeptical of a significant human influence on climate.
In 2012, while temporarily based at the Netherlands Environmental Assessment Agency (PBL), my colleagues and I conducted a detailed survey about climate science. More than 1800 international scientists studying various aspects of climate change, including e.g. climate physics, climate impacts and mitigation, responded to the questionnaire. The main results of the survey have now been published in Environmental Science and Technology (doi: 10.1021/es501998e).
Level of consensus regarding attribution
The answers to the survey showed a wide variety of opinions, but it was clear that a large majority of climate scientists agree that anthropogenic greenhouse gases are the dominant cause of global warming. Consistent with other research, we found that the consensus is strongest for scientists with more relevant expertise and for scientists with more peer-reviewed publications. 90% of respondents with more than 10 climate-related peer-reviewed publications (about half of all respondents), agreed that anthropogenic greenhouse gases (GHG) are the dominant driver of recent global warming. This is based on two different questions, of which one was phrased in similar terms as the quintessential attribution statement in IPCC AR4 (stating that more than half of the observed warming since the 1950s is very likely caused by GHG).
Posted on 10 August 2014 by John Hartz
Air pollution and climate change could mean 50% more people going hungry by 2050, new study finds* by Roz Pidcock has generated a very lively comment thread. The posts by SkS authors and other SkS regulars contain a wealth of quality information.
*This is a repost of an article originally published on The Carbon Brief.
El Niño Watch
The El Niño that seems to be trying to form in the tropical Pacific Ocean is looking a little less likely now, though the chances of it developing are still double the normal odds, forecasters said in the latest monthly update on the cyclical climate phenomenon, released Thursday.
That update lowered the odds of an El Niño occurring in fall and early winter to 65 percent, down from 80 percent last month. But “we’re still fairly confident that El Niño will come,” said Michelle L’Heureux a meteorologist with the National Oceanic and Atmospheric Administration’s Climate Prediction Center, who puts out the El Niño forecasts along with the International Research Institute for Climate and Society at Columbia University.
Odds of El Niño Drop; Still Expected to Form by Andrea Thompson, Climate Central, Aug 7, 2014
Toon of the Week
h/t to I heart Climate Scientists
Posted on 9 August 2014 by John Hartz
- Air traffic growth set to outpace carbon reduction efforts
- Conservative media is now just making things up about climate scientists
- Deep emissions cuts needed by 2050 to limit warming-UN draft
- EPA chief: Teach global warming in schools
- Europe's forests 'particularly vulnerable' to rapid climate change
- Heading into the late innings on climate change
- Naomi Klein: 'Our Economic Model Is at War with Life on Earth'
- Odds of El Niño drop; still expected to form
- Reality check: Most scientists never believed in "Global Cooling"
- Sowing confusion about renewable energy
- The toxic algae are not done with Toledo. Not by a long stretch.
- Which ocean species will outlast the rising acidity of seawater?
Air traffic growth set to outpace carbon reduction efforts
Carbon reduction efforts in the airline industry will be outweighed by growth in air-traffic, even if the most contentious mitigation measures are implemented, according to new research by the University of Southampton.
Even if proposed mitigation measures are agreed upon and put into place, air traffic growth-rates are likely to out-pace emission reductions, unless demand is substantially reduced.
"There is little doubt that increasing demand for air travel will continue for the foreseeable future," says co-author and travel expert Professor John Preston. "As a result, civil aviation is going to become an increasingly significant contributor to greenhouse gas emissions."
Air traffic growth set to outpace carbon reduction efforts, Phys.org, Aug 7, 2014
Posted on 8 August 2014 by Guest Author
This is a re-post from Roz Pidcock at Carbon Brief
The combination of rising temperatures and air pollution could substantially damage crop growth in the next 40 years, according to a new paper. And if emissions stay as high as they are now, the number of people who don't get enough food could grow by half by the middle of the century.
Feeding the world's rapidly growing population is a serious concern.
Research shows rising temperatures are likely to lead to lower crop yields. Other work suggests air pollution might reduce the amount of food produced worldwide. But nobody has considered both effects together, say the paper's authors.
The two effects are closely related as warmer temperatures increase the production of ozone in the atmosphere. Here's lead author Professor Amos Tai from the Chinese University of Honk Kong to explain.
Posted on 7 August 2014 by dana1981
While there’s a 97% consensus among climate science experts and their research that humans are causing climate change, only about 67% of Americans believe global warming is even happening, including 25% of Tea Party members and 61% of other Republicans. Only about half of Americans realize that humans are causing global warming.
Social scientists have been investigating this disconnect between the evidence and expert consensus, and public opinion. Is it caused by information deficit and misinformation surplus, political and ideological biases, or some combination of these factors?
There’s one school of thought among social scientists that information just doesn’t matter – in fact, it might even be polarizing. In essence, liberals feel as though they’re on Team ‘global warming is a problem caused by humans’ while conservatives identify with Team ‘no it’s not.’ Some social scientists believe this cultural identity is so strong that scientific evidence, facts, and information can’t break through it. A 2012 study led by Yale’s Dan Kahan seemed to support this idea, finding that conservatives who are more scientifically literate are less worried about global warming.
However, that study looked at general science literacy. A new paper led by Sophie Guy, published in the European Journal of Social Psychology, looks at climate-specific knowledge and ideology. The authors conducted a survey of a national sample of 335 Australians and tested their climate knowledge by asking them to correctly identify factors that are and aren’t causing the rise in atmospheric greenhouse gases (for example, deforestation, automobiles, pesticides, and ozone depletion). They also asked participants, “How much do you feel you know about climate change?,” about their climate-related beliefs, and their ideology. The authors concluded,
...[climate] knowledge dampened the negative influence of individualist ideology on belief in climate change.
Individualists favor small government and self-sufficiency, in line with the libertarian wing of the Republican Party. Individualists were less likely than communitarians (those who think interdependence is an important part of society, i.e. “it takes a village”) to believe that climate change is happening. However, individualists with high climate-specific knowledge were significantly more likely to accept the climate is changing than those with low climate knowledge.
Posted on 6 August 2014 by John Hartz
- 40 million people depend on the Colorado River. Now it's drying up.
- Climate change talks: Equity Reference Framework fails
- Climate scientists dub this year’s El Niño “a real enigma”
- Farming practices and climate change at root of Toledo water pollution
- First summit on women and climate decries lack of grassroots funding
- For most of us, global warming has become 'normal' climate
- India: US wants to link power pacts with climate change agreement
- Mysterious craters are just the beginning of Arctic surprises
- Putting a climate context on southern California's flash floods
- Shattering myths to help the climate
- Toledo’s algae bloom in line with climate projections
- Tornado outbreaks could have a climate change assist
- Want to have a real impact on climate change?
- Warmer seas change UK fish stock as cod head north
- Will climate change lead to conflict or cooperation?
40 million people depend on the Colorado River. Now it's drying up.
Science papers don't generate much in the way of headlines, so you'll be forgiven if you haven't heard of one called "Groundwater Depletion During Drought Threatens Future Water Security of the Colorado River Basin," recently published by University of California-Irvine and NASA researchers.
But the "water security of the Colorado River basin" is an important concept, if you are one of the 40 million people who rely on the Colorado River for drinking water, a group that includes residents of Las Vegas, Los Angeles, Phoenix, Tucson, and San Diego. Or if you enjoy eating vegetables like broccoli, cauliflower, and spinach during the winter. Through the many diversions, dams, canals, and reservoirs the river feeds as it snakes its way from the Rockies toward Mexico, the Colorado also provides the irrigation that makes the desert bloom in California's Imperial Valley and Arizona's Yuma County—source of more than two-thirds of US winter vegetable production.
40 Million People Depend on the Colorado River. Now It's Drying Up. by Tom Philpott, Mother Jones, Aug 4, 2014