Not exact matches
Biello: A lot
of scientists that I've spoken to think we have no chance
of meeting 450 ppm given that we haven't done hardly anything to
change our course and there are other scientists who say that we have already well past kind
of the safe point for
concentration of the
greenhouse gases in the atmosphere.
But critics like Fugere said that Exxon Mobil may be missing the bigger picture, especially
in light
of the most recent findings from the Intergovernmental Panel on Climate
Change, which hold that the world is already witnessing the harsh realities of climate change and that conditions will worsen unless steps are taken quickly to reduce greenhouse gas concentrations (ClimateWire, Marc
Change, which hold that the world is already witnessing the harsh realities
of climate
change and that conditions will worsen unless steps are taken quickly to reduce greenhouse gas concentrations (ClimateWire, Marc
change and that conditions will worsen unless steps are taken quickly to reduce
greenhouse gas concentrations (ClimateWire, March 31).
However, solar variability alone can not explain the post-1970 global temperature trends, especially the global temperature rise
in the last three decades
of the 20th Century, which has been attributed by the Inter-Governmental Panel on Climate
Change (IPCC) to increased
concentrations of greenhouse gases in the atmosphere.»
Climate
change caused by rising
concentrations of greenhouse gases in the atmosphere is causing more extreme rainfall and snowfall — and floods
«There is a certain ironic satisfaction
in seeing a study funded by the Koch Brothers — the greatest funders
of climate
change denial and disinformation on the planet — demonstrate what scientists have known with some degree
of confidence for nearly two decades: that the globe is indeed warming, and that this warming can only be explained by human - caused increases
in greenhouse gas concentrations,» he wrote.
The study does a «very nice job»
of using different approaches to show that climate
change is a dominant force, says Thomas Lovejoy, president
of the H. John Heinz III Center for Science, Economics, and the Environment
in Washington, D.C. «I think the single most important public policy [issue] here is agreeing on what the limit should be on
greenhouse gas concentration,» he says.
Taking factors such as sea surface temperature,
greenhouse gases and natural aerosol particles into consideration, the researchers determined that
changes in the
concentration of black carbon could be the primary driving force behind the observed alterations to the hydrological cycle
in the region.
This represents a shift
in the usual analysis
of climate
change, particularly
in international negotiations, which tend to focus on how much
concentrations of greenhouse gases in the atmosphere will rise by a particular date.
Although the process is energy - and water - intensive, there is hope it could play a role
in reducing the
concentration of greenhouse gases in the atmosphere and minimizing the impact
of climate
change on the rest
of the world.
Already, the planet's average temperature has warmed by 0.7 degree C, which is «very likely» (greater than 90 percent certain) to be a result
of the rising
concentrations of greenhouse gases in the atmosphere, according to the U.N. Intergovernmental Panel on Climate
Change.
It increases the ability to predict how
changes in land use or climate warming could affect the sources and global
concentrations of greenhouse gases in the atmosphere.
For the RCP8.5 projections, which represents stronger increases
in greenhouse gas concentrations than RCP4.5, there was a striking level
of consistency
in the magnitude
of change in AR frequency — all models showed an approximate doubling
of the number
of future ARs compared to the simulations for 1980 — 2005.
«Detailed chemical measurements
in Antarctic ice cores show that massive, halogen - rich eruptions from the West Antarctic Mt. Takahe volcano coincided exactly with the onset
of the most rapid, widespread climate
change in the Southern Hemisphere during the end
of the last ice age and the start
of increasing global
greenhouse gas concentrations,» according to McConnell, who leads DRI's ultra-trace chemical ice core analytical laboratory.
And those feedbacks ultimately determine the extent to which that initial warming will be amplified, but they don't even
change the fact that you elevate
greenhouse gas concentrations in the atmosphere and you'll get a warming
of the surface.
«This underscores that large, sustained
changes in global temperature like those observed over the last century require drivers such as increased
greenhouse gas concentrations,» said lead author Patrick Brown, a PhD student at Duke's Nicholas School
of the Environment.
Non-polar glacial ice holds a wealth
of information about past
changes in climate, the environment and especially atmospheric composition, such as variations
in temperature, atmospheric
concentrations of greenhouse gases and emissions
of natural aerosols or human - made pollutants... The glaciers therefore hold the memory
of former climates and help to predict future environmental
changes.
In the Central Hardwoods, the effects of a changing climate are expected to include rising temperatures due to a rise in greenhouse gas concentrations, leading to longer growing season
In the Central Hardwoods, the effects
of a
changing climate are expected to include rising temperatures due to a rise
in greenhouse gas concentrations, leading to longer growing season
in greenhouse gas concentrations, leading to longer growing seasons.
The researchers warn, however, that the future evolution
of the AMO remains uncertain, with many factors potentially affecting how it interacts with atmospheric circulation patterns, such as Arctic sea ice loss,
changes in solar radiation, volcanic eruptions and
concentrations of greenhouse gases in the atmosphere.
The reason may well be climate
change caused by increasing
concentrations of atmospheric
greenhouse gases — now roughly 390 parts per million, up from 280 ppm
in the 1700s.
At the same time, even if California meets its ambitious target, it may not make a huge dent
in the atmospheric
concentrations of greenhouse gases causing climate
change.
«It is true that there are other factors (such as volcanism, the
changes in the orbit and the axis
of the Earth, the solar cycle), but numerous scientific studies indicate that most
of the global warming
in recent decades is due to the large
concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxide and others) mainly emitted due to human activity.»
In the midst of an unseasonably warm winter in the Pacific Northwest, a comparison of four publicly available climate projections has shown broad agreement that the region will become considerably warmer in the next century if greenhouse gas concentrations in the atmosphere rise to the highest levels projected in the the Intergovernmental Panel on Climate Change (IPCC) «business - as - usual» scenari
In the midst
of an unseasonably warm winter
in the Pacific Northwest, a comparison of four publicly available climate projections has shown broad agreement that the region will become considerably warmer in the next century if greenhouse gas concentrations in the atmosphere rise to the highest levels projected in the the Intergovernmental Panel on Climate Change (IPCC) «business - as - usual» scenari
in the Pacific Northwest, a comparison
of four publicly available climate projections has shown broad agreement that the region will become considerably warmer
in the next century if greenhouse gas concentrations in the atmosphere rise to the highest levels projected in the the Intergovernmental Panel on Climate Change (IPCC) «business - as - usual» scenari
in the next century if
greenhouse gas concentrations in the atmosphere rise to the highest levels projected in the the Intergovernmental Panel on Climate Change (IPCC) «business - as - usual» scenari
in the atmosphere rise to the highest levels projected
in the the Intergovernmental Panel on Climate Change (IPCC) «business - as - usual» scenari
in the the Intergovernmental Panel on Climate
Change (IPCC) «business - as - usual» scenario.
To me the very fact that we have been inducing major
changes in the
concentration of greenhouse gases is alarming.
These rising atmospheric
greenhouse gas concentrations have led to an increase
in global average temperatures
of ~ 0.2 °C decade — 1, much
of which has been absorbed by the oceans, whilst the oceanic uptake
of atmospheric CO2 has led to major
changes in surface ocean pH (Levitus et al., 2000, 2005; Feely et al., 2008; Hoegh - Guldberg and Bruno, 2010; Mora et al., 2013; Roemmich et al., 2015).
ACPI assumes a 1 percent annual increase
in the rate
of greenhouse gas concentrations through the year 2100, for little
change in precipitation and an average temperature increase
of 1.5 to 2 degrees centigrade at least through the middle
of 21st century.
Climate
change scenarios are based on projections
of future
greenhouse gas (particularly carbon dioxide) emissions and resulting atmospheric
concentrations given various plausible but imagined combinations
of how governments, societies, economies, and technologies will
change in the future.
For example,
changes in Earth's atmospheric composition (especially the
concentrations of greenhouse gases) may alter the climate, while climate
change itself can
change the atmospheric composition (for example by
changing the rate at which weathering removes CO2).
«While there is substantial uncertainty
in both the pace
of change and the ultimate amounts
of warming following an increase
in greenhouse gas concentration,» Caldeira said, «there is little uncertainty
in the basic outlook.
[2] According to the Intergovernmental Panel on Climate
Change (IPCC), most
of the observed increase
in global average temperatures since the mid-20th century is very likely due to the observed increase
in human
greenhouse gas concentrations.
Global climate
change will occur as a result
of global warming resulting from the
greenhouse effect caused by the retention
of heat
in the lower atmosphere
of the Earth caused by the
concentration of gases of various kinds.
Res — math.ku.dk ``... Evidence is mounting that
changes in global surface temperature can be attributed to human activities that increase the atmospheric
concentration of greenhouse gases and tropospheric sulfates [Sanier et al, 1996a, 1996b].
But there are vast volumes
of studies concluding that rising
concentrations of greenhouse gases are already influencing the climate and will continue to raise the odds
of fiercer floods, drier droughts and other disruptive
changes, including a quickening pace
of coastal retreats (and all as human populations soar
in some
of the world's most vulnerable places).
[Andy Revkin — Above, Mr. McCain appears to be using references to observed
changes in ice and climate to fend off potential criticism from a small, but vocal array
of climate scientists and conservative or anti-regulatory groups that disparage computer simulations showing the consequences
of rising
greenhouse -
gas concentrations.]
If we knew ocean heat uptake as well as we know atmospheric temperature
change, then we could pin down fairly well the radiative imbalance at the top
of the atmosphere, which would give us a fair indication
of how much warming is «
in the pipeline» given current
greenhouse gas concentrations.
As soon as his paper was published (1861)
in the Proceedings
of the Royal Society, he put out a press release for the London newspapers explaining that this result implied that all past climate
changes were now understood and all future climate
changes could be predicted simply from a knowledge
of the
concentrations of these «
greenhouse»
gases...
Growing populations and growing energy demand will greatly increase atmospheric
concentrations of greenhouse gases in this century without big
changes in technology, policy, or behavior.
However, as will be discussed below, it is still not possible to accurately predict the magnitude (if any), timing or impact
of climate
change as a result
of the increase
in greenhouse gas concentrations.
With the warming already committed
in the climate system plus the additional warming expected from rising
concentrations of greenhouse gases in the atmosphere, the Arctic will experience significant
changes during this century even if
greenhouse gas emissions are stabilized globally at a level lower than today's.
This was a relatively stable climate (for several thousand years, 20,000 years ago), and a period where we have reasonable estimates
of the radiative forcing (albedo
changes from ice sheets and vegetation
changes,
greenhouse gas concentrations (derived from ice cores) and an increase
in the atmospheric dust load) and temperature
changes.
The report
of Susan Solomon's National Research Council Committee on Stabilization Targets for Atmospheric
Greenhouse Gas Concentrations is the place to go to see a collection
of impacts that have already been observed and will be amplified as the climate
changes in ways that have been quantitatively estimated.
Changes in this balance over time lead to the changes in greenhouse gas concentrations that have been observed to occur on geological (millions of year) time
Changes in this balance over time lead to the
changes in greenhouse gas concentrations that have been observed to occur on geological (millions of year) time
changes in greenhouse gas concentrations that have been observed to occur on geological (millions
of year) timescales.
Paul Voosen, one
of the most talented journalists probing human - driven climate
change and related energy issues, has written an award - worthy two - part report for Greenwire on one
of the most enduring sources
of uncertainty
in climate science — how the complicated response
of clouds
in a warming world limits understanding
of how hot it could get from a given rise
in greenhouse gas concentrations:
To me the very fact that we have been inducing major
changes in the
concentration of greenhouse gases is alarming.
This finding is consistent with the expected effect
of increasing
greenhouse gas concentrations and with other observed evidence
of a
changing climate such as reductions
in Arctic sea ice extent, melting permafrost, rising sea levels, and increases
in heavy downpours and heat waves.
Note that part
of the uncertainy
in all this is the time uncertainty — from the ice core records, we can pick a rather precise time and look at a rather precise number for
greenhouse gas concentrations, but pinning down the magnitude albedo
change at exactly the same time (since albedo is not globally uniform, obviously) is impossible.
As to the specific papers you cited, Miller et al 2006 states,» Recent
changes in the magnitude
of the annular patterns have been interpreted as the signature
of anthropogenic forcing by
changes in the
concentration of greenhouse gases (GHGs) or else stratospheric ozone [Shindell et al., 1999; Fyfe et al., 1999; Kushner et al., 2001; Kindem and Christiansen, 2001; Sexton, 2001; Gillett and Thompson, 2003; Shindell and Schmidt, 2004; Arblaster and Meehl, 2006].»
Carbon dioxide removal addresses the root cause
of climate
change — high
concentrations of the
greenhouse gas in the atmosphere — and generally have well - understood benefits and risks, but current technologies would take decades to achieve moderate results and be cost - prohibitive at scales large enough to have a sizeable impact.
Most discussions about adapting to inevitable climate
change in a world with rising
concentrations of greenhouse gases have focused on seawalls, drought - resistant crops and the like.
The team's results show that human - induced (anthropogenic)
changes in well - mixed
greenhouse gases, which are fairly evenly distributed
in the atmosphere, and ozone, a
greenhouse gas that is found
in higher
concentrations in the stratosphere, are the primary causes
of the approximately 200 - meter rise
in the tropopause that has occurred since 1979.
Recognizes that warming
of the climate system is unequivocal and that most
of the observed increase
in global average temperatures since the mid twentieth century is very likely due to the increase
in anthropogenic
greenhouse gas concentrations, as assessed by the Intergovernmental Panel for Climate
Change in its Fourth Assessment Report;