Sentences with phrase «achieved by human emissions»

The evidence of the size of climate zone shifts and the associated changes in atmospheric heights from Mediaeval Warm Period to Little Ice Age to date suggests that the natural solar and ocean induced changes in the effective radiating height are far greater than anything that could be achieved by human emissions.

Not exact matches

And achieving any stabilization target — whether 2 degrees C of warming or 450 ppm or 1,000 gigatons of carbon added to the atmosphere by human activity — will require at least an 80 percent cut in emissions from peak levels by the end of this century and, ultimately, zero emissions over the long term.

Quick progress in curbing emissions of carbon dioxide, the main human - generated greenhouse gas, could be achieved by using capital from rich countries to help prevent the destruction of tropical forests (and resulting greenhouse - gas emissions), Mr. Gore said.

For example, one of the scenarios included in the IPCC's latest assessment assumes aggressive emissions reductions designed to limit the global temperature increase to 3.6 °F (2 °C) above pre-industrial levels.3 This path would require rapid emissions reductions (more than 70 % reduction in human - related emissions by 2050, and net negative emissions by 2100 — see the Appendix 3: Climate Science, Supplemental Message 5) sufficient to achieve heat - trapping gas concentrations well below those of any of the scenarios considered by the IPCC in its 2007 assessment.

It is a simple way to monitor the overall consistency between the evolving climate change signal, individual countries» pledges and the overall goal of achieving net zero CO2 emissions by the time we reach 2 °C of human - related warming.

The US apparent unwillingness to reduce its greenhouse gas emissions beyond what it is already on track to achieve is of considerable controversy in the Qatar negotiations this week because of the growing scientific concern about the potential inevitability of catastrophic warming caused by human activities.

Of course, if humans started to reduce greenhouse gas emissions by 6 % a year right now, the end of the century challenge would be to take 150 billion tonnes from the atmosphere, and most of this could be achieved simply by better forest and agricultural management, according to a new study in the journal Earth System Dynamics.

We therefore examine the human health benefits of increasing 21st - century CO2 reductions by 180 GtC, an amount that would shift a «standard» 2 °C scenario to 1.5 °C or could achieve 2 °C without negative emissions.