56.
What does the text
mainly tell us?
A. Importance of
attending parties. B. Tips on
an important social skill.
C. How to make use of
associations. D. How to recite and
repeat names.
E
The world’s oceans have
warmed 50 percent faster over the last 40 years than previously thought due to
climate change, Australian and US climate researchers reported on Wednesday.
Higher ocean temperatures expand the volume of water, contributing to a rise in
sea levels that is submerging small island nations and threatening to great
damage in low-lying, densely-populated delta regions around the globe.
The study, published in
the British journal Nature, adds to a growing scientific chorus of warnings
about the pace and consequences of rising oceans. It also serves as a
corrective to a massive report issued last year by the Nobel-winning UN
Intergovernmental Panel on Climate Change(IPCC),
according to the authors.
Rising sea levels are
driven by two things: the thermal(热)expansion of sea water,
and additional water from melting sources of ice. Both processes are caused by
global warming. The ice sheet that sits at the top of Greenland, for example,
contains enough water to raise world ocean levels by seven metres(23
feet),
which would bury sea-level cities from Dhaka to Shanghai.
Trying to figure out how
much each of these factors contributes to rising sea levels is critically
important to understanding climate change, and forecasting future temperature
rises, scientists say. But up to now, there has been a confusing gap between
the projections of computer-based climate models, and the observations of
scientists gathering data from the oceans.
The new study, led by
Catia Domingues of the Centre for Australian Weather and Climate Research, is
the first to reconcile(与…一致)the models with observed
data. Using new techniques to assess ocean temperatures to a depth of 700
metres(2,300 feet)from 1961 to 2003, it
shows that thermal warming contributed to a 0. 53 millimetre-per-year rise in
sea levels rather than the 0. 32 mm rise reported by the IPCC.
