In parched California, rainfall patterns are essentially the same as they were 120 years ago, but humans have made it warmer and that added heat is driving the state’s crippling drought, according to a new study. Warm temperatures dry out soils and cause precipitation to fall as rain rather than snow, thus reducing annual snowpack essential for irrigation, for example. What snow does fall then melts earlier in the spring.
A temperature rise that could cause irreversible and potentially catastrophic damage to human civilization is practically inevitable, according to rising chatter among experts in the lead up to a year of key negotiations on a new climate change global accord.
World leaders have voluntarily committed to limit warming by the end of the century to 2 degrees Celsius (3.6 degrees Fahrenheit) above the pre-industrial level, a threshold beyond which, scientists argue, severe drought, rising seas and supercharged storms as well as food and water security become routine challenges.
Given the world’s historic emissions combined with a continued reliance on fossil fuels to power humanity for the foreseeable future, limiting the increase to 2 degrees Celsius is all but impossible, according to David Victor, a professor of international relations and an expert on climate change policy at the University of California, San Diego.
Nearly a quarter century ago, Greg Johnson was a freshly minted PhD in oceanography puttering north in the South Pacific Ocean. About every 35 miles, the boat he was on stopped and scientists dropped an instrument overboard to measure temperature and salinity at regular intervals all the way to the seafloor.
This process was repeated in a crisscross pattern throughout the world’s oceans over the course of the 1990s. “At the end of it, we had kind of a blurred snapshot of the state of the ocean in that decade all the way from the surface to the bottom from coast to coast,” he explained to NBC News.
The following decade, scientists re-sampled some transects for the sake of comparison. Taken together, the measurements collected during the World Ocean Circulation Experiment are the best — and for most of the oceans only — data available on temperature and salinity 1.4 miles below the surface.
Today, Johnson is spearheading a project to deploy a global array of robotic floats that will probe to a depth of 3.75 miles, allowing scientists to continuously monitor changing temperature and salinity in the entire ocean except for the deepest trenches.
Experts are more certain than ever that human activity is changing the global climate, even though they don’t fully understand every detail of the climate system, according to a new report released Wednesday by two of the world’s leading scientific bodies.
The document from the U.S. National Academy of Sciences and the United Kingdom’s Royal Society aims to move the climate change debate beyond humans’ role in global warming to a discussion of how to limit the impacts on society.
“Climate change is happening. We see it in temperature, we see it in the melting ice, and we see it in sea-level rise,” Inez Fung, an atmospheric scientist at the University of California at Berkeley and a co-lead author of the report, told NBC News. The changes are due to rising atmospheric concentrations of carbon dioxide with a chemical signature from the burning of fossil fuels, she added.
For the past 13 years, global surface air temperatures have hardly budged higher despite continual pumping of planet-warming gasses into the atmosphere from the engines of modern life. Does this prove global warming is a giant hoax? No, according to a new study, which says the missing heat is being blown into the western Pacific Ocean by extraordinarily powerful and accelerating trade winds.
“Their acceleration over the last couple of decades is way stronger than you’ve ever seen in a climate model, about twice as strong,” Matthew England, a climate scientist at the University of New South Wales in Sydney, Australia, told NBC News. “This is an unprecedented level of strengthening and it is strong enough that it is actually pushing heat in the Pacific Ocean into the ocean’s interior,” he added.
As the heat is drawn down into the ocean’s interior, cooler water rises to the surface and cools air temperatures. When — it’s not a matter of if, noted England — the winds slacken, the heat stored in the Pacific Ocean will return to the atmosphere, allowing the surface air temperatures to spike higher and “catch up to the original projections of global warming in under a decade.”
The emergence of a newly identified atmospheric pattern is likely to provide two to three weeks advance warning that a stifling and potentially deadly heat wave will hit the U.S., according to a new study. Since current forecasts go out no more than 10 days, the additional notice could give homeowners, farmers, electric companies and hospitals critical time to prepare for severe heat.
The precursor is a so-called “wavenumber 5” pattern, a sequence of alternating high and low pressure systems — five each — that ring the northern mid-latitudes several miles above the Earth’s surface, according the research published Sunday in the journal Nature Geoscience.
The world is hurtling toward a stark future where the web of life unravels, human cultures are uprooted, and millions of species go extinct, according to a new study. This doomsday scenario isn’t far off, either: It may start within a decade in parts of Indonesia, and begin playing out over most of the world — including cities across the United States — by mid-century.
What’s more, even a serious effort to stabilize spiraling greenhouse gas emissions will only stave off these changes until around 2069, notes the study from the University of Hawaii, Manoa, published online Wednesday in the journal Nature. The authors warn that the time is now to prepare for a world where even the coldest of years will be warmer than the hottest years of the past century and a half.