Summary: All over the world unprecedented weather extremes are occurring, with profound effects on human activities and health. This post reports some recent climate events. These instances are consistent with the forecasts that climate scientists have been making for several decades. The IPCC issued a new, more urgent report in October 2018 specifying that we have to keep the world temperature increase below 1.5°C above pre-industrial levels, primarily by eliminating all emissions worldwide in about two decades.
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Tidal
flooding, Eastern U. S. Many cities
along the Eastern seacoast of the U. S. already suffer fair-weather tidal
flooding due to rising sea levels. According
to the U. S. National Oceanic and Atmospheric Administration (NOAA) as reported
by National Public Radio (NPR), tidal flooding is worsening in more than 40 U. S. coastal cities. Most of these flood days are not related to storm
activity, but rather to rising sea level.
Tides are worst, i.e., highest, when the moon is full or new. This image
Source:
NPR All Things Considered https://www.npr.org/programs/all-things-considered/2019/07/10/740176584
shows
downtown Annapolis, MD, founded three centuries ago on the shores of Chesapeake
Bay, flooded during a high tide in 2017.
As NPR reports, NOAA finds that tidal flooding events in Annapolis have
increased by 925% over the last 50 years.
The city is planning a Flood Mitigation Project in conjunction with many
agencies including the U. S. Naval Academy, which is located in Annapolis.
Charleston,
SC is also suffering from worsening ocean flooding (NPR). The city is built on a low-lying
peninsula, exposed to the sea. In
addition, in recent years flooding has been aggravated by extreme rainfall. Both of these factors result from worsening
global warming. The city issues flood
warnings as frequently as weekly during the summer. Its officials now understand they must plan
for 2-3 feet (0.6-0.9 m) of flooding over the next 50 years.
Temperatures
for January-May 2019 for most regions around the globe are warmer than average
or set warmest records, whereas only a very few regions were cooler than
average (see the following image).
Source:
NOAA National Centers for Environmental Information, State of the
Climate: Global Climate Report for May 2019, published online June 2019,
retrieved on July 10, 2019; https://www.ncdc.noaa.gov/sotc/global/201905
.
The
average is for the 30-year reference period from 1981-2010. It is seen that for the vast majority of global
surface pixels the 5-month averages were mildly or much warmer than the 30-year
reference period. In an accompanying
graphic NOAA shows land and ocean temperature departures from the 30 year reference period
for the January-May interval annually from 1880 to the present (not shown). Starting about 1976 the departures are all
only positive, trending up to 0.8-1.1°C
(1.4-2.1°F) above the
average between 2015 and 2019. The full
139-year record shows clearly that, although there are year-to-year variations,
the long-term trend in the 5-month global average temperature has been
gradually increasing by about 1.3°C
(2.3°F) starting at
about 1910.
Global
warming has been determined to have caused two current climate extremes. First, a severe heat wave blanketed much of
western Europe during the end of June 2019.
It broke heat records across much of the area. A group of experts in the field of climate
attribution examined the temperature data in two ways, as described in a
commentary in the journal Nature.
Attribution
science has made great strides in recent years.
In this case, the scientists examined the heat wave in two ways. First, they compared the actual temperature
record with results from climate models for the European region, running cases
that included or excluded a man-made greenhouse effect. They found that the record heat was five
times more likely with extra greenhouse gases than without. Second, they assessed whether historical
records going back 100 years are consistent with the actual heat wave data when
climate models are used to “hindcast” the data.
They found that global warming and air pollution made the current heat
wave 100 times more likely than without those factors.
More
generally, the commentary summarizes that about two-thirds of the 200
attribution inquiries reported to date have positively identified global
warming as making the particular event being studied more likely or more severe
than without warming.
Second,
a report from India describes “Zero Day, the day when a city’s taps dry out and
people have to stand in line to collect a daily quota of water.” This is currently happening in many Indian
states
because aquifers are being over-drawn and this year’s monsoon rains were 30% less
abundant than usual. The image below
exemplifies the disaster:
Women
in Rajasthan, India walk long distances to collect drinking water.
Source:
Nature India, https://www.natureasia.com/en/nindia/article/10.1038/nindia.2019.84?WT.ec_id=NINDIA-20190710&sap-outbound-id=124373C6B945724353776A88CBC27CF245889A7F&mkt-key=005056B0331B1ED888DF526EE5C22187.
Zero
Day has already occurred in the city of Chennai, and is predicted to happen
next year in many cities, including the capital, Delhi. In all 600 million people may be impacted. Groundwater is the source for most of India’s
rural inhabitants and for its agriculture.
The Ministry of Drinking Water and Sanitation states that global warming
is one factor contributing to this crisis.
Analysis
The
Paris Agreement of December 2015 pledged 193 members of the United Nations
voluntarily to reduce greenhouse gas emission rates sufficiently to keep the
planet below a 2°C rise above
pre-industrial levels by 2100. But the
Agreement is failing; the rate of emissions is still increasing, raising the
total accumulated greenhouse gas burden of the atmosphere. As a result, the IPCC issued a new, more
drastic report in October 2018
specifying
that we have to keep that temperature increase below 1.5°C, and to reach a worldwide reduction of
emission rates to zero by about 2040, or 21 years from now.
Failing
to achieve this goal will lead to more intense warming, and will contribute to
more rapid sea level rise, impacting coastal cities around the world, as discussed
above. It will also contribute to the more
intense extremes of heat, such as Europe has experienced, as well as more
extreme heat and aridity such as India is experiencing.
The
economic harm alone is problematic, since in general our political structures
don’t budget for funds to revive the losses, and insurance may be inadequate or
nonexistent. All people of the world
have to mobilize individually and politically to eliminate fossil
fuel use and develop a renewable energy economy to achieve the goal of zero
emissions.
© 2019 Henry Auer
