Tag: human activity

bookmark_borderThe Cumulative Costs of Climate Change

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“The crisis carries a profound warning. As climate change brings more frequent and intense storms, floods, heat waves, wildfires and other extreme events, it is placing growing stress on the foundations of the country’s economy: Its network of roads and railways, drinking-water systems, power plants, electrical grids, industrial waste sites and even homes. Failures in just one sector can set off a domino effect of breakdowns in hard-to-predict ways,” as reported by The New York Times in the article Texas Blackouts Point to Coast-to-Coast Crises Waiting to Happen.

“We are colliding with a future of extremes,” said Alice Hill, who oversaw planning for climate risks on the National Security Council during the Obama administration. “We base all our choices about risk management on what’s occurred in the past, and that is no longer a safe guide.”

“Sewer systems are overflowing more often as powerful rainstorms exceed their design capacity. Coastal homes and highways are collapsing as intensified runoff erodes cliffs. Coal ash, the toxic residue produced by coal-burning plants, is spilling into rivers as floods overwhelm barriers meant to hold it back. Homes once beyond the reach of wildfires are burning in blazes they were never designed to withstand.”

“I am extremely concerned by the lack of emergency-management expertise reflected in Biden’s climate team,” said Samantha Montano, an assistant professor at the Massachusetts Maritime Academy who focuses on disaster policy. “There’s an urgency here that still is not being reflected.”

A White House spokesman, Vedant Patel, said in a statement, “Building resilient and sustainable infrastructure that can withstand extreme weather and a changing climate will play an integral role in creating millions of good paying, union jobs” while cutting greenhouse gas emissions.

“All these issues are converging,” said Robert D. Bullard, a professor at Texas Southern University who studies wealth and racial disparities related to the environment. “And there’s simply no place in this country that’s not going to have to deal with climate change.”

bookmark_borderDisappearing Ice Sheets, Glaciers and Arctic Sea Ice

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The U.N.’s panel on global warming warns:

Over the last two decades, the Greenland and Antarctic ice sheets have been losing mass, glaciers have continued to shrink almost worldwide, and Arctic sea ice and Northern Hemisphere spring snow cover have continued to decrease in extent (high confidence).

• The average rate of ice loss 8 from glaciers around the world, excluding glaciers on the periphery of the ice sheets 9, was very likely 226 [91 to 361] Gt yr−1 over the period 1971−2009, and very likely 275 [140 to 410] Gt yr −1 over the period 1993−2009 10. {4.3}
• The average rate of ice loss from the Greenland ice sheet has very likely substantially increased from 34 [–6 to 74] Gt yr –1 over the period 1992–2001 to 215 [157 to 274] Gt yr –1 over the period 2002–2011. {4.4}
• The average rate of ice loss from the Antarctic ice sheet has likely increased from 30 [–37 to 97] Gt yr –1 over the period 1992–2001 to 147 [72 to 221] Gt yr –1 over the period 2002–2011. There is very high confidence that these losses are mainly from the northern Antarctic Peninsula and the Amundsen Sea sector of West Antarctica.
• The annual mean Arctic sea ice extent decreased over the period 1979–2012 with a rate that was very likely in the range 3.5 to 4.1% per decade (range of 0.45 to 0.51 million km 2 per decade), and very likely in the range 9.4 to 13.6% per decade (range of 0.73 to 1.07 million km 2 per decade) for the summer sea ice minimum (perennial sea ice). The average decrease in decadal mean extent of Arctic sea ice has been most rapid in summer (high confidence); the spatial extent has decreased in every season, and in every successive decade since 1979 (high confidence). There is medium confidence from reconstructions that over the past three decades, Arctic summer sea ice retreat was unprecedented and sea surface  temperatures were anomalously high in at least the last 1,450 years. {4.2, 5.5}
• It is very likely that the annual mean Antarctic sea ice extent increased at a rate in the range of 1.2 to 1.8% per decade (range of 0.13 to 0.20 million km 2 per decade) between 1979 and 2012. There is high confidence that there are strong regional differences in this annual rate, with extent increasing in some regions and decreasing in others. {4.2}
• There is very high confidence that the extent of Northern Hemisphere snow cover has decreased since the mid-20th century (see Figure SPM.3). Northern Hemisphere snow cover extent decreased 1.6 [0.8 to 2.4] % per decade for March and April, and 11.7 [8.8 to 14.6] % per decade for June, over the 1967–2012 period. During this period, snow cover extent in the Northern Hemisphere did not show a statistically significant increase in any month. {4.5}
• There is high confidence that permafrost temperatures have increased in most regions since the early 1980s. Observed warming was up to 3°C in parts of Northern Alaska (early 1980s to mid-2000s) and up to 2°C in parts of the Russian European North (1971–2010). In the latter region, a considerable reduction in permafrost thickness and areal extent has been observed over the period 1975–2005 (medium  confidence). {4.7}
• Multiple lines of evidence support very substantial Arctic warming since the mid-20th century. {Box 5.1, 10.3}

bookmark_borderWhy Doesn’t Global Warming Feel Warmer?

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The Intergovernmental Panel on Climate Change (IPCC) has released its Fifth Assessment Report (AR5). The report states that “warming of the climate system is unequivocal.”

Then, why doesn’t it feel that much hotter? Because most of the rise in temperature is in the water:

Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence). It is virtually certain that the upper ocean (0?700 m) warmed from 1971 to 2010, and it likely warmed between the 1870s and 1971.

• On a global scale, the ocean warming is largest near the surface, and the upper 75 m warmed by 0.11 [0.09 to 0.13] °C per decade over the period 1971–2010. Since AR4, instrumental biases in upper-ocean temperature records have been identified and reduced, enhancing confidence in the assessment of change.
• It is likely that the ocean warmed between 700 and 2000 m from 1957 to 2009. Sufficient observations are available for the period 1992 to 2005 for a global assessment of temperature change below 2000 m. There were likely no significant observed temperature trends between 2000 and 3000 m for this period. It is likely that the ocean warmed from 3000 m to the bottom for this period, with the largest warming observed in the Southern Ocean.
• More than 60% of the net energy increase in the climate system is stored in the upper ocean (0–700 m) during the relatively well-sampled 40-year period from 1971 to 2010, and about 30% is stored in the ocean below 700 m. The increase in upper ocean heat content during this time period estimated from a linear trend is likely.
• It is about as likely as not that ocean heat content from 0–700 m increased more slowly during 2003–2010 than during 1993–2002. Ocean heat uptake from 700–2000m, where interannual variability is smaller, likely continued unabated from 1993 to 2009.
• It is very likely that regions of high salinity where evaporation dominates have become more saline, while regions of low salinity where precipitation dominates have become fresher since the 1950s. These regional trends in ocean salinity provide indirect evidence that evaporationand precipitation over the oceans have changed (medium confidence).
• There is no observational evidence of a trend in the Atlantic Meridional Overturning Circulation (AMOC), based on the decade-long record of the complete AMOC and longer records of individual AMOC components.

bookmark_borderU.N.: Humans Induce Climate Change

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UN Secretary-General Ban Ki-moon warned that “we cannot accept a rising tide that floats only some boats and leaves many to drown.”

Ban Ki-moon has been taking a strong stance on global warming. His latest efforts include getting world leaders to admit humans are impacting climate change. Most people would think this is a given. No. In fact, quite a few government and business leaders refuse to admit to what science shows.

“Nobody can benefit from catastrophic climate change or rampant unemployment and the social unrest that comes with it,” Mr. Ban said.

UK newspaper The Independent says. “The UN’s Intergovernmental Panel on Climate Change (IPCC) will say next week that certainty has increased from “very likely” to “extremely likely” that human activity has caused more than half of the observed temperature rise from 1951 to 2010, in a large part due to fossil fuels and deforestation.”