Large -
scale ocean circulation changes beyond the 21st century can not be reliably assessed because of uncertainties in the meltwater supply from the Greenland ice sheet and model response to the warming.
The activists say warmer weather will «possibly» set in motion «large -
scale ocean circulation changes.»
We know, however, that rapid warming of the planet increases the risk of crossing climatic points of no return, possibly setting in motion large -
scale ocean circulation changes, the loss of major ice sheets, and species extinctions.
Not exact matches
«The study demonstrates a robust century -
scale link between
ocean circulation changes in the Atlantic basin and rainfall in the adjacent continents during the past 4,000 years,» said UTIG Director Terry Quinn, a co-author on the study.
He believes that no one has thought of combining the two theories before because it's not an intuitive idea to look at how the effects of
changing patterns of
ocean circulation, which occur on time
scales of thousands of years, would effect global silicate weathering, which in turn controls global climate on time
scales of 100s of thousands of years.
And what we see is both how complex climate
changes can be and how profound an effect
changing patterns of
ocean circulation can have on global climate states, if looked at on a geological time
scale.»
Millennial -
scale glacial variability versus Holocene stability:
Changes in planktic and benthic foraminifera faunas and
ocean circulation in the North Atlantic during the last 60,000 years.
Suppose also that — DESPITE THIS STABILIZING MECHANISM some as - yet unknown
ocean circulation cycle operates that is the sole cause of the Holocene centennial
scale fluctuations, and that this cycle has reversed and is operating today, yielding a temperature
change that happens to mimic what models give in response to radiative forcing
changes.
There is considerable confidence that Atmosphere -
Ocean General
Circulation Models (AOGCMs) provide credible quantitative estimates of future climate
change, particularly at continental and larger
scales.
For weather predictions, accuracy disappears within a few weeks — but for
ocean forecasts, accuracy seems to have decadal
scale accuracy — and when you go to climate forcing effects, the timescale moves toward centuries, with the big uncertainties being ice sheet dynamics,
changes in
ocean circulation and the biosphere response.
Suppose also that — DESPITE THIS STABILIZING MECHANISM some as - yet unknown
ocean circulation cycle operates that is the sole cause of the Holocene centennial
scale fluctuations, and that this cycle has reversed and is operating today, yielding a temperature
change that happens to mimic what models give in response to radiative forcing
changes.
There is so little understanding about how the
ocean parses its response to forcings by 1) suppressing (local convective
scale) deep water formation where excessive warming patterns are
changed, 2) enhancing (local convective
scale) deep water formation where the
changed excessive warming patterns are co-located with increased evaporation and increased salinity, and 3) shifting favored deep water formation locations as a result of a) shifted patterns of enhanced warming, b) shifted patterns of enhanced salinity and c) shifted patterns of
circulation which transport these enhanced
ocean features to critically altered destinations.
Especially at the regional
scale,
ocean and atmospheric
circulation changes are clearly also important.
The available data are insufficient to say if the
changes in O2 are caused by natural variability or are trends that are likely to persist in the future, but they do indicate that large -
scale changes in
ocean physics influence natural biogeochemical cycles, and thus the cycles of O2 and CO2 are likely to undergo
changes if
ocean circulation changes persist in the future.
There are
changes in
ocean and atmospheric
circulation — and cloud — at multidecadal
scales.
A new study helps clarify how past and future coastal sea level
changes are related to local winds and large -
scale ocean circulation.
The interaction of
ocean circulation, which serves as a type of heat pump, and biological effects such as the concentration of carbon dioxide can result in global climate
changes on a time
scale of decades.
A new study, published in Journal of Geophysical Research -
Oceans, helps clarify how past and future coastal sea level
changes are related to local winds and large -
scale ocean circulation.
I was based in the Meteorology Department, but my work focused on understanding the large -
scale circulation of the
ocean and how it responds to
change.
«In 2007 a team of NASA and university scientists has detected an ongoing reversal in Arctic
Ocean circulation triggered by atmospheric
circulation changes that vary on decade - long time
scales.
This basin - wide
change in the Atlantic climate (both warming and cooling) induces a basin -
scale sea surface temperature seesaw with the Pacific
Ocean, which in turn modifies the position of the Walker
circulation (the language by which the tropical basins communicate) and the strength of the Pacific trade winds.
The large interannual to decadal hydroclimatic variability in winter precipitation is highly influenced by sea surface temperature (SST) anomalies in the tropical Pacific
Ocean and associated
changes in large -
scale atmospheric
circulation patterns [16].
The most natural type of long term variability is in my view based on slowly varying
changes in
ocean circulation, which doesn't necessarily involve major transfer of heat from one place to another but influences cloudiness and other large
scale weather patterns and through that the net energy flux of the Earth system.
These millennial -
scale teleconnections resulted from the bipolar seesaw behaviour of the Atlantic
Ocean related to changes in the ocean circula
Ocean related to
changes in the
ocean circula
ocean circulation.
«-- A team of NASA and university scientists has detected an ongoing reversal in Arctic
Ocean circulation triggered by atmospheric
circulation changes that vary on decade - long time
scales.
By 2006 some models still found that
changes in the
ocean circulation «are able to produce abrupt climate
changes on decadal to centennial time
scales,» Randall et al. (2007), p. 641.
By the way, we also did a paper on millennial -
scale solar geoengineering (Cao et al, 2016) showing that, in at least one climate model, solar geoengineering behaves quite well on the 1000 - year time
scale with no substantial long term growth in climate
change as
ocean circulation and such adjusts to the new conditions.
And as the for the reason for this year's Arctic ice melt, NASA and university scientists have detected an ongoing reversal in Arctic
Ocean circulation triggered by atmospheric
circulation changes that varies on decade - long time
scales.
Among the global -
scale tipping points identified by earth scientists are the collapse of large ice sheets in Greenland and Antarctica,
changes in
ocean circulation, feedback processes by which warming triggers more warming, and the acidification of the
ocean.h
There are three groups of tipping elements: melting ice bodies,
changing circulations of the
ocean and atmosphere, and threatened large -
scale ecosystems.
This is the first extensive survey of one of these fjords that shows us how these warm waters circulate and how vigorous the
circulation is...
changes in the large -
scale ocean circulation of the North Atlantic are propagating to the glaciers very quickly — not in a matter of years, but a matter of months.
9.3.1 Global Mean Response 9.3.1.1 1 % / yr CO2 increase (CMIP2) experiments 9.3.1.2 Projections of future climate from forcing scenario experiments (IS92a) 9.3.1.3 Marker scenario experiments (SRES) 9.3.2 Patterns of Future Climate
Change 9.3.2.1 Summary 9.3.3 Range of Temperature Response to SRES Emission Scenarios 9.3.3.1 Implications for temperature of stabilisation of greenhouse gases 9.3.4 Factors that Contribute to the Response 9.3.4.1 Climate sensitivity 9.3.4.2 The role of climate sensitivity and
ocean heat uptake 9.3.4.3 Thermohaline
circulation changes 9.3.4.4 Time - scales of response 9.3.5 Changes in Variability 9.3.5.1 Intra-seasonal variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 Conc
changes 9.3.4.4 Time -
scales of response 9.3.5
Changes in Variability 9.3.5.1 Intra-seasonal variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time - scale variability 9.3.5.4 Summary 9.3.6 Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 Conc
Changes in Variability 9.3.5.1 Intra-seasonal variability 9.3.5.2 Interannual variability 9.3.5.3 Decadal and longer time -
scale variability 9.3.5.4 Summary 9.3.6
Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on changes in extremes of weather and climate 9.3.6.6 Conc
Changes of Extreme Events 9.3.6.1 Temperature 9.3.6.2 Precipitation and convection 9.3.6.3 Extra-tropical storms 9.3.6.4 Tropical cyclones 9.3.6.5 Commentary on
changes in extremes of weather and climate 9.3.6.6 Conc
changes in extremes of weather and climate 9.3.6.6 Conclusions
This in turn helps explain how factors such as fresh water from melting ice or
changes in global wind patterns might lead to large -
scale changes in
ocean circulation or climate in the future.
Abrupt climate
changes, such as the collapse of the West Antarctic Ice Sheet, the rapid loss of the Greenland Ice Sheet or large -
scale changes of
ocean circulation systems, are not considered likely to occur in the 21st century, based on currently available model results.
Furthermore, by homogenizing the entire
ocean into a single metric, they miss important nuances of local and regional
scale redox
changes that might reflect the activity of climatic feedback processes, such as weathering,
ocean circulation change, or temperature
change.
The discharge of Eurasian rivers draining into the Arctic
Ocean shows an increase since the 1930s (Peterson et al., 2002), generally consistent with
changes in temperature and the large -
scale atmospheric
circulation.