In addition, there are numerous uncertainties in the climate models themselves, due to the challenge of numerically simulating all relevant aspects of the climate system
over long timescales of decades to centuries.
Not exact matches
Our distinctive contribution was to look at government costs and performance
over a much
longer timescale than had been attempted before and we believe our own study will contribute to transparency and accountability through our unique publicly - available compilation
of consistent
long - term time - series
of official data.
Some Labour MPs and the Green MP, Caroline Lucas, dismissed the offer as unacceptable, saying it represented only 12 refugees a day
over the course
of this parliament, adding that 20,000 sounded less impressive given the
long timescale.
Until now, changes in the relative proportion
of rare mutations, that could be both detrimental and adaptive, had only been shown
over relatively
long timescales, by comparing African and European populations.
«Additionally,
over a
longer timescale, by keeping close connection between astrophysicists and climate researchers, this programme will aid in the understanding
of our own changing climate.»
Michel Bouchon
of Joseph Fourier University in Grenoble, France, is also monitoring the Earth's movement, but
over a much
longer timescale.
They demonstrated that species showing faster rates
of genetic differentiation between populations are more likely to produce greater numbers
of species
over long evolutionary
timescales.
Collisions take place
over very
long timescales compared to the length
of our lifetime — several tens
of millions
of years.
Though typical galaxy collisions take place
over what to us seems a
long timescale, they are short compared to the lifetimes
of galaxies.
In a paper published in Science Advances, he proposes that mass extinction occurs if one
of two thresholds are crossed: For changes in the carbon cycle that occur
over long timescales, extinctions will follow if those changes occur at rates faster than global ecosystems can adapt.
«Our results indicate that [Proxima Centauri b] and similar exoplanets are generally not capable
of supporting an atmosphere
over sufficiently
long timescales when the stellar wind pressure is high,» Dong said.
«It is surprising, but Earth's atmosphere is about 50 trillion metric tons in mass, and so
over long enough
timescales — hundreds, thousands, even millions
of years — all
of that mass, and its drag across the surface
of the planet, can have an effect,» said study author Caleb Scharf, director
of astrobiology at Columbia University in New York.
Climate scientists would say in response that changes in ocean circulation can't sustain a net change in global temperature
over such a
long period (ENSO for example might raise or lower global temperature on a
timescale of one or two years, but
over decades there would be roughly zero net change).
Climate impacts research is in its infancy compared to science on the physical climate, for a number
of reasons: attributing cause and effect isn't easy; neither is collecting data
over timescales and regions
long and large enough such that it's possible to draw any meaningful trends from their analysis.
It's not necessarily the case that relative trajectories
of OHC and surface temperature have to be congruent
over these
long timescales.
Our results support the use
of short - term manipulative experiments spanning weeks as proxies to understand the potential effects
of global change forcing on diatom community structure
over longer timescales such as years.
Ricarda Winkelmann et al. modeled the response
of the Antarctic ice sheet to a wide range
of future carbon emissions scenarios
over the
long - term (previous simulations have mainly looked at changes that might occur on a shorter
timescale).
Over very long time periods such that the carbon cycle is in equilibrium with the climate, one gets a sensitivity to global temperature of about 20 ppm CO2 / deg C, or 75 ppb CH4 / deg C. On shorter timescales, the sensitivity for CO2 must be less (since there is no time for the deep ocean to come into balance), and variations over the last 1000 years or so (which are less than 10 ppm), indicate that even if Moberg is correct, the maximum sensitivity is around 15 ppm CO2 / deg C. CH4 reacts faster, but even for short term excursions (such as the 8.2 kyr event) has a similar sensitiv
Over very
long time periods such that the carbon cycle is in equilibrium with the climate, one gets a sensitivity to global temperature
of about 20 ppm CO2 / deg C, or 75 ppb CH4 / deg C. On shorter
timescales, the sensitivity for CO2 must be less (since there is no time for the deep ocean to come into balance), and variations
over the last 1000 years or so (which are less than 10 ppm), indicate that even if Moberg is correct, the maximum sensitivity is around 15 ppm CO2 / deg C. CH4 reacts faster, but even for short term excursions (such as the 8.2 kyr event) has a similar sensitiv
over the last 1000 years or so (which are less than 10 ppm), indicate that even if Moberg is correct, the maximum sensitivity is around 15 ppm CO2 / deg C. CH4 reacts faster, but even for short term excursions (such as the 8.2 kyr event) has a similar sensitivity.
The release
of carbon dioxide and methane from the Arctic will provide a positive feedback to climate change which will be more important
over longer timescales — millennia and
longer.
Over longer timescales, the number
of households using natural gas for space heating has increased — for example, in the Northeast, households are switching their heating fuel from heating oil to natural gas.
It would require a much stronger relationship
of temperature driving CO2 than occurred during the ice age — interglacial oscillations (and it is also important to remember that those changes occurred
over much
longer timescales too... which is the presumed reason why there is a several hundred year lag time between temperatures starting to rise or fall and CO2 starting to rise or fall).
Determining the position
of the SPCZ
over longer timescales in the past (pre-20th century) has been studied using coral records
of the southwest Pacific.
Some
of these episodes are based on climatology (i.e., averages
over decadal
timescales) as previously mentioned, so they don't allow the study
of interannual variability but do give strong evidence
of prevailing conditions in the
longer term; this is especially true
of the southern hemisphere.
Market forces are largely ineffective in mitigating against Global Warming since markets tend to be relatively short term in comparison to the slightly
longer timescales over which we will feel the full effects
of GW.
Global Temperature is an example
of a bulk property, and it does indeed average out
over sufficient time scales; hence showing that whatever chaos, spatio - temporal or otherwise, is present in the system on short
timescales it does not affect our
longer term predictions.
The correspondence to obvserved changes in C02 on
timescales of a couple
of years,
over the satellite era and to the degree seen even
over the 20th century, makes it difficult not to conclude that sources involed in changes
of C02 on short
timescales are also involved in its change on
long timescales.
Excellent work as usual, Bob, but you won't be surprised that I'm still trying to see how your ENSO material can be worked into the climate cycling from MWP to LIA to date without some other force altering the relative strengths
of El Nino and La Nina
over longer timescales than the multidecadal.
This study, which was supported by the U.S. National Science Foundation, is the first to analyze
long - term trends in rainfall and surface air temperature
over a
timescale of nearly an entire century, the study's lead author, Natalie Thomas, a doctoral candidate in atmospheric and oceanic science at the University
of Maryland, told Live Science.
The researches thus «urge extreme caution in attributing short - term trends (i.e.
over many decades and
longer) in US tropical cyclone losses to anthropogenic climate change,» stating that «anthropogenic climate change signals are unlikely to emerge in US tropical cyclone losses on
timescales of less than a century under the projections examined here.»
Conversely, rural people in many parts
of the world have,
over long timescales, adapted to climate variability, or at least learned to cope with it.
To me, these results, in aggregate, convey an idea
of the
timescale over which the chaotic fluctuations probably dominated (relatively short intervals), and the
longer timescale over which the forced response to the GHGs was dominant.
The notion that
over the
longer timescales, forced responses dominated (at least for the second half
of the past century) is reinforced by data on Ocean Heat Uptake since 1955.
I know
of no reason why the apparent averaging out
of short term fluctuations
over longer timescales dominated by forcing was an inevitable result that could have been derived without reference to the actual data.
We do not understand the interactions
of a complex system sufficiently and the
timescales over which ECS may be reached may well be
longer than humans care about.
The potential change in the radiative restoration strength
over longer timescales is also considered, resulting in a likely (67 %) range
of 1.5 — 2.9 K for equilibrium climate sensitivity, and a 90 % confidence interval
of 1.2 — 5.1 K
To measure how the system has shifted
over long timescales, researchers collected
long cores
of sediment from the sea floor.
Over long enough
timescales the initial conditions problem (i.e. one
of chaos and weather) breaks down into a boundary conditions problem (i.e. governed by forcings), which can be resolved using an ENSEMBLE
of models run with a variety
of initial conditions.
Only
over climate
timescales (typically, 30 years or more), do the
long - term trends emerge that reflect the influence
of changes in atmospheric levels
of carbon dioxide.»
I calculate Delta GT carbon = 6.5 * Delta T + 0.48 * emitted carbon, which I make to convert to 2.8 ppmv per degree C. That's much less than your figure, but given the
timescales one would expect much more outgassing
over a
longer period because a greater quantity
of water will warm.
Because
of the time lags involve in the climate system, short - term changes can be very difficult to predict, but
over a
long enough
timescale, these kinds
of effects become all but certain.
Assuming a CR - cloud connection exists, there are various factors which could potentially account for a lack
of detection
of this relationship
over both
long and short
timescales studies, including: uncertainties, artefacts and measurement limitations
of the datasets; high noise levels in the data relative to the (likely low) amplitude
of any solar - induced changes; the inability
of studies to effectively isolate solar parameters; or the inability to isolate solar - induced changes from natural climate oscillations and periodicities.
Climate impacts research is in its infancy compared to science on the physical climate, for a number
of reasons: attributing cause and effect isn't easy; neither is collecting data
over timescales and regions
long and large enough such that it's possible to draw any meaningful trends from their analysis.
Components
of the Earth's climate system that vary
over long timescales, such as ice sheets and vegetation, could have an important effect on this temperature sensitivity, but have often been neglected.
Climate scientists would say in response that changes in ocean circulation can't sustain a net change in global temperature
over such a
long period (ENSO for example might raise or lower global temperature on a
timescale of one or two years, but
over decades there would be roughly zero net change).
Debates
over discounting are longstanding in climate analysis, but as my colleague Jerry Taylor wrote last year, economists who study climate change are inclined to choose lower discount rates because
of the inter-generational transfers and
long timescales associated with climate change.
When in balance, primary production and respiration processes result in large diel variability (Table 2), but are essentially CO2 - neutral; however,
over longer timescales, spatial and / or temporal decoupling
of these processes can change pH drastically (Borges and Gypens 2010; Provoost et al. 2010; Cai et al. 2011).
Another point he makes regards the speed
of the change in CO2 levels and that somehow overwhelming negative feedbacks that would otherwise occur if the change in CO2 levels happened
over a
longer timescale.
Halting the production
of marine biota C and maintaining the same fluxes
of C out
of marine biota, the marine biota C would be used up in about 3 weeks, at which point a 0.0022 % / year ** drawdown
of O2 could persist for some
longer time (** the actual removal
of O2 from the atmosphere via oxidation in the deeper ocean may occur
over a
timescale of 1000 years, but the oxydation
of organic C in the ocean might be completed
over a significantly shorter time, so the actual removal
of O2 from the atmosphere may be slower than 0.0022 % / year)-- but it still wouldn't have much total effect on the amount
of atmospheric O2.
Climate is not the «variation»
of weather
over longer timescales.
Because climate is the variation
of weather
over longer timescales.