Sentences with phrase «uncertainty than emission»

Not exact matches

However, the high luminosity of the primary star, intense Ca II H and K emission (Smith and Dominy, 1979), and radial velocity variations somewhat larger than can be accounted for by the expected uncertainties suggested that Delta Eridani might be an RS CVn - type binary and therefore a photometric variable like most members of that class.

This large uncertainty makes it difficult for a cautious policy maker to avoid either: (1) allowing warming to exceed the agreed target; or (2) cutting global emissions more than is required to satisfy the agreed target, and their associated societal costs.

In fact it is the opposite — Hansen is actually claiming that the uncertainty in models (for instance, in the climate sensitivity) is now less than the uncertainty in the emissions scenarios (i.e. it is the uncertainty in the forcings, that drives the uncertainty in the projections).

Over the short time scales considered, the model uncertainty is larger than the uncertainty coming from the choice of emission scenario; for sea level it completely dominates the uncertainty (see e.g. the graphs in our Science paper).

What is clear is that uncontrolled emissions will very soon put us in range of temperatures that have been unseen since the Eemian / Stage 5e period (about 120,000 years ago) when temperatures may have been a degree or so warmer than now but where sea level was 4 to 6m higher (see this recent discussion the possible sensitivities of the ice sheets to warming and the large uncertainties involved).

When the emission estimates are compared over time, the resulting relative uncertainty is generally lower than the uncertainty of estimates for individual years.

The uncertainty is so large because ± 4 W m - 2 of annual long wave cloud forcing error is ± 114» larger than the annual average 0.035 Wm - 2 forcing increase of GHG emissions since 1979.

To project future emissions from human activities, we used the SRES higher (A1FI) and lower (B1) emissions scenarios that capture to some extent the uncertainty in future climate due to human decisions [22], with CO2 emissions ranging from slightly less than present - day levels up to four times present - day levels by 2100.

For tropospheric ozone, uncertainties in physical processes are more important than uncertainties in precursor emissions.

For the near future the uncertainty in climate prediction justifies choosing polices that guide us towards net negative emissions as quickly as possible and the stabilization of atmospheric greenhouse gases at levels significantly lower than today.

The main argument for a carbon tax rather than a trading scheme is that, if there is a lot of uncertainty about the cost of reducing emissions, and not much uncertainty about the damage caused by climate change, a fixed price for emissions (that is, a tax) will get closer to the optimal outcome than a fixed quantity.

Uncertainty about the magnitude of methane emissions from leaking wells makes it difficult for federal and provincial regulators to identify and set up programs to control methane emissions, a much more potent greenhouse gas than CO2.

One thing that is different about the climate change issue is that most of the uncertainty is in when rather than if CO2 emissions will cause serious environmental and economic damage.

The reason for the «wild range» of model predictions has much more to do with the uncertainty in how emissions will play out in the coming century than it does in the climate sensitivity to CO2 forcing.

But capping emissions on a fixed schedule would produce its own uncertainties: if alternatives to fossil fuels (e.g., renewables, efficiencies, carbon sequestration) materialized more slowly than planned, demand would not be met and price rises would ensue.

Should a developed nation such as the United States which has much higher historical and per capita emissions than other nations be able to justify its refusal to reduce its ghg emissions to its fair share of safe global emissions on the basis of scientific uncertainty, given that if the mainstream science is correct, the world is rapidly running out of time to prevent warming above 2 degrees C, a temperature limit which if exceeded may cause rapid, non-linear climate change.

Note that there's some uncertainty over how high, exactly, China's emissions are expected peak in 2030, but no matter what assumptions you use, they're expected to peak much higher (the orange lines) than what would be required under «inertia» or «equity» approaches to stay below 2 °C:

I don't have any problem with the fact that there are many time frames over which atmospheric CO2 would respond if emissions were to stop, though I think there is far more uncertainty in the estimates of response over time than is usually acknowledged, and that people with «agendas» consistently discount the response times that do not support their policy positions.

Additional escalation of the mining impact occurs as conventional oil mining is supplanted by tar sands development, with mining and land disturbance from the latter producing land use - related greenhouse gas emissions as much as 23 times greater than conventional oil production per unit area [152], but with substantial variability and uncertainty [152]--[153].

The constraints mean that any appeal to uncertainty must imply a stronger, rather than weaker, need to cut greenhouse gas emissions than in the absence of uncertainty.

You clearly believe that nothing should be done today to reduce emissions because given the uncertainty about the future, every policy will be less than the forecast error of 2050?

• Poles to tropics temperature gradient, average temp of tropics over past 540 Ma; and arguably warming may be net - beneficial overall • Quotes from IPCC AR4 WG1 showing that warming would be beneficial for life, not damaging • Quotes from IPCC AR5 WG3 stating (in effect) that the damage functions used for estimating damages are not supported by evidence • Richard Tol's breakdown of economic impacts of GW by sector • Economic damages of climate change — about the IAMs • McKitrick — Social Cost of Carbon much lower than commonly stated • Bias on impacts of GHG emissions — Figure 1 is a chart showing 15 recent estimates of SCC — Lewis and Curry, 2015, has the lowest uncertainty range.

Assumptions and uncertainties associated with climate scenarios (Randall et al., 2007) are not considered here, other than to identify the greenhouse gas emission trends or socio - economic development pathways (e.g., SRES, Naki?enovi?

The difference between Professor Nordhaus's optimal carbon tax policy and a fifty - year delay policy is insignificant economically or climatologically in view of major uncertainties in (1) future economic growth (including reductions in carbon emissions intensity); (2) the physical science (e.g., the climate sensitivity); (3) future positive and negative environmental impacts (e.g., the economic «damage function»); (4) the evaluation of long - term economic costs and benefits (e.g., the discount rate); and (5) the international political process (e.g., the impact of less than full participation).

In the end, it's the emissions and concentrations that most matter rather than uncertainties about climate sensitivity.

For years economists have been showing that when uncertainty exists over the costs of reducing emissions of a pollutant like C02 it is better to use a tax than a quota.

I understood Selby to say that natural sources and sinks are much larger, vary much more, and have much higher uncertainties than anthropogenic emissions.

Uncertainties in the estimates of global dust emissions are greater than a factor of two (Zender et al., 2004) due to problems in validating and modelling the global emissions.

«Given this uncertainty [over the environmental and economic effects of CO2 emissions], and the historic failure of central planning to do anything other than undermine economic welfare, the editor, Colin Robinson, one of the country's leading energy economists, argues that it is prudent to proceed with caution.

-LRB-... besides to point out that «the uncertainty in climate projections associated with the physical climate model is smaller than the uncertainty associated with the models of emission scenarios that are used to project carbon dioxide emissions»)