than I’d ever witnessed before and many communities near where I live
are now being required to raise their homes up. What is the prognosis
for sea level rise in the years immediately ahead? — Scott P.,
Since sea level measurements were first recorded, in 1870, global
averages have risen almost eight inches. The annual rate of rise has
been 0.13 inches over the past 20 years, which is close to twice the
average from the previous 80 years. Future estimates for sea levels
vary according to region but most Earth scientists agree that sea
levels are expected to rise at a greater pace than during the last 50
Predicting the amount of rise is an inexact science and depends on
many factors including climate change and ice sheet flows. The U.S.
National Research Council predicts a possible sea level rise of
between 22 and 29 inches over the 21st century in the U.S. Sea levels
are anticipated to continue rising for centuries.
According to the U.S. Environmental Protection Agency (EPA), land
elevation changes also have a large impact on the effects of rising
water levels. Subsidence (sinking) or uplift (rising) of the land can
help determine the relative sea level rise. The EPA’s relative sea
level estimates, assuming a two foot global sea level rise by 2100,
are 2.3 feet at New York City, 2.9 feet at Hampton Roads, Virginia,
3.5 feet at Galveston, Texas and one foot at Neah Bay in Washington
The main factors contributing to sea level rise are thermal expansion
(created by an increase in ocean water temperatures) and the melting
of ice caps and glaciers. Human activities, such as the burning of
fossil fuels, combined with natural activities, have contributed to
the rise of the earth’s surface temperature over the past century.
According to National Geographic, about 80 percent of this additional
heat is absorbed by the oceans. The above factors are well studied,
but more research is still being done on how climate change will
impact large ice sheets in areas such as Greenland and the Antarctic.
An extra foot of sea level rise could be a possibility depending on
what happens with these larger ice sheets.
Even small changes in sea levels can have adverse effects on coastal
areas. Erosion, flooding of wetlands, aquifer and agricultural soil
contamination and habitat loss for fish, birds and plants are all
problems resulting from rising sea levels. Also, higher sea levels
usually mean more destructive weather events as storm surges get
bigger and more powerful and devastate everything in their way.
Coastal communities will suffer the most, as flooding from rising
water levels will force millions of people out of their homes.
As for what can be done, reducing our collective carbon footprint is
no doubt the first and most important step. Individuals should drive
and fly less, walk and bicycle more and take advantage of public
transit. But sweeping policy changes will have the most impact: A
recent commitment by the Obama White House to require coal-burning
power plants and other large industrial operations to minimize
greenhouse gas emissions should finally help get the United States
started on the right track, but many wonder if such moves represent
too little too late.
* * * * *
Dear EarthTalk: I know that some of us are genetically predisposed to
get cancer, but what are some ways we can avoid known environmental
triggers for it? — B. Northrup, Westport, MA
Cancer remains the scourge of the American health care system, given
that four out of every 10 of us will be diagnosed with one form or
another during out lifetime. Some of us are genetically predisposed
toward certain types of cancers, but there is much we can do to avoid
exposure to carcinogens in our environment.
According to the Environmental Working Group (EWG), a non-profit
working to protect public health and the environment, a key first step
in warding off cancer is lifestyle change — “stopping smoking,
reducing drinking, losing weight, exercising and eating right.” The
American Cancer Society reports that smoking and poor nutrition each
account for about one-third of the 575,000 U.S. cancer deaths each
But smoking and obesity are obvious and other cancer triggers aren’t
so easily pinpointed. In 2010 the President’s Cancer Panel reported
that environmental toxins play a significant and under-recognized role
in many cancers, causing “grievous harm” to untold numbers of
Americans. And EWG reports that U.S. children are born “pre-polluted”
with up to 200 carcinogenic substances already in their bloodstreams.
Given this shocking fact, it may seem futile to try to reduce our
bodies’ chemical burden, but it could be a matter of life and death.
EWG lists several ways anyone can cut their cancer risk. First up is
to filter our tap water, which can include arsenic, chromium and
harmful chemicals. Simple carbon filters or pitchers can reduce
contaminants, while more costly reverse osmosis filters can filter out
arsenic or chromium.
The foods we choose also play a role in whether or not we get cancer.
Eating lots of fruits and vegetables is healthy, but not if they are
laden with pesticides. Going organic when possible is the best way to
reduce pesticide exposure. And when organic foods aren’t available,
stick with produce least likely to contain pesticides (check out EWG’s
“Clean 15” list of conventional crops containing little if any
pesticide residue). EWG also suggests cutting down on high-fat meats
and dairy products: “Long-lasting cancer-causing pollutants like
dioxins and PCBs accumulate in the food chain and concentrate in
Eliminating stain- and grease-proofing chemicals (Teflon, Scotchgard,
etc.) is another way to cut cancer risks. “To avoid them,” says EWG,
“skip greasy packaged foods and say no to optional stain treatments in
the home.” And steer clear of BPA, a synthetic estrogen found in some
plastic water bottles, canned infant formula and canned foods. “To
avoid it, eat fewer canned foods, breast feed your baby or use
powdered formula, and choose water bottles free of BPA,” reports EWG.
Personal care products and cosmetics can also contain carcinogens.
EWG’s “Skin Deep” cosmetics database flags particularly worrisome
products and green-lights others that are healthy.
Another cancer prevention tip is to seal wooden outdoor decks and
playsets — those made before 2005 likely contain lumber
“pressure-treated” with carcinogenic arsenic in order to stave off
insect infestations. Of course, avoiding too much sun exposure — and
wearing high-SPF sunscreen — when using those decks and playsets is
another important way to hedge one’s bets against cancer.