Study: our Paris carbon budget may be 40% smaller than thought

Study: our Paris carbon budget may be 40% smaller than thought

SOURCE: The Guardian DATE: July 24, 2017 SNIP: In the Paris climate treaty, nearly every world country agreed to try and limit global warming to no more than 2°C above pre-industrial temperatures, and preferably closer to 1.5°C. But a new study published in Nature Climate Change notes that the agreement didn’t define when “pre-industrial” begins. According to the last IPCC report, to have a 50% chance of staying below the 2°C target, when accounting for non-carbon greenhouse gases, we have a remaining budget of about 300bn tons of carbon dioxide. But that was for 2°C warming above late-1800 temperatures. If we add another 0.1°C of pre-industrial warming, the study authors estimated that the budget shrinks by 60bn tons (20%), and if there was an additional 0.2°C pre-industrial warming, the 2°C carbon budget shrinks by...
Allowable ‘carbon budget’ most likely overestimated

Allowable ‘carbon budget’ most likely overestimated

SOURCE: Phys.org DATE: July 24, 2017 SNIP: “The IPCC research community uses a definition of preindustrial that is likely underestimating the warming that has already taken place,” said Michael Mann, distinguished professor of atmospheric science and director, Earth System Science Center, Penn State. “That means we have less carbon to burn than we previously thought, if we are to avert the most dangerous changes in climate.” [The researchers] found that assuming the traditional late 19th-century baseline and using the highest future emissions scenario, by the middle of this century, the temperature rise will likely be about 4 degrees C (5 degrees F). With a moderate emissions scenario, the researchers found that keeping below 2 degrees C was still unlikely. Only the most aggressive scenario for reducing carbon emissions is likely to keep the temperature rise to 2 degrees C or...
Climate scientists may have been underestimating global warming, finds study

Climate scientists may have been underestimating global warming, finds study

SOURCE: The Independent DATE: July 24, 2017 SNIP: Preventing global warming from becoming “dangerous” may have just got significantly harder after new research suggested climate scientists have been using the wrong baseline temperature. The amount of global warming is often measured relative to the late 19th century even though this is about 100 years after the start of the industrial revolution, when humans started burning large amounts of fossil fuels. Now an international team of scientists has suggested that the Earth’s true “pre-industrial” temperature could be up to 0.2 degrees Celsius cooler. One of the researchers, Professor Michael Mann, said the Intergovernmental Panel on Climate Change (IPCC) had been using a definition of pre-industrial “that is likely underestimating the warming that has already taken place”. “That means we have less carbon to burn than we previously thought, if we are to avert the most dangerous changes in climate,” he...
March set a remarkable new record for global warming, NOAA reports

March set a remarkable new record for global warming, NOAA reports

SOURCE: Think Progress DATE: April 19, 2017 SNIP: The National Oceanic and Atmospheric Administration (NOAA) reported that last month set an unusual and unexpected new record for global warming. No month before March 2017 had ever exceeded the “normal” temperature (the 1981–2010 average) by a full 1.8°F (1.0°C) — “in the absence of an El Niño episode in the tropical Pacific Ocean.” NOAA reports that both March and the year to date (January through March) were the “second warmest on record” for the world since global temperature records began in 1880. They were second only to 2016 which, of course, was a year marked by a major El Niño. Significantly, both March and Janurary-March 2017 beat their 2015 counterparts easily — even though all of 2015 had El Niño...
A warm climate is more sensitive to changes in carbon dioxide

A warm climate is more sensitive to changes in carbon dioxide

SOURCE: Science Daily DATE: November 10, 2016 SNIP: A new study, published this week in Science Advances and led by Tobias Friedrich from the International Pacific Research Center (IPRC) at the University of Hawaii at Mānoa (UHM), concludes that warm climates are more sensitive to changes in CO2 levels than cold climates. The researchers project that by the year 2100, global temperatures will rise 5.9°C (~10.5°F) above pre-industrial values. This magnitude of warming overlaps with the upper range of estimates presented by the Intergovernmental Panel on Climate Change...