Environmental Sciences, asked by Anonymous, 1 year ago

global warming project in shorts observation and conclusion. in Hindi or English language.

Answers

Answered by mehul1045
6
Summary

Scientific knowledge about climate change is being improved all the time through research into the climate system, climate forcing, climate variations and changes, and climate effects. 
The knowledge base is well established when it comes to the fundamental physics behind the greenhouse effect and the fact that the average surface temperature has increased over the past 50 years. It is also highly likely that most of the observed warming is due to human impact on the climate. 

At the same time there is considerable uncertainty regarding the consequences of climate change and how much emissions need to decrease to achieve a set climate target. Knowledge about climate sensitivity is the most important factor in calculating how much greenhouse gases we can emit for a given temperature target. 

Research shows that considerable emission reductions are required to achieve the two-degree target. To achieve a lower temperature target of, for instance, 1.5°C, even greater emission reductions are needed.



Conclusions

This review highlights the knowledge base for climate work from a scientific perspective, based on the assignment the Swedish government gave to SMHI at the end of May 2011 (M2011/2166/Kl). The focus is on: (i) how new knowledge and new research results influence previous conclusions about climate change and climate effects, (ii) scientific prerequisites for the two-degree target, and (iii) scientific prerequisites for a 1.5-degree target.

The main conclusions are as follows:

The knowledge relating to climate sensitivity reported in AR4 (IPCC 2007a) still is timely. New research into how natural carbon sinks and carbon sources are influenced by climate change indicates, however, that the future net carbon uptake terrestrial systems could be less than formerly estimated.There are now far more studies and information about emission pathways compared to when AR4 was published. The studies inform primarily about the two-degree target, rather than even lower temperature targets.Measures to reduce emissions of short-lived climate forcers such as tropospheric ozone and soot may help in limiting global warming in the near term, but such measures are not sufficient to curb the warming.The later global emissions culminate, the lower the probability of the two-degree target being met. In order to meet the two-degree target with a relatively high probability (around 70%), global greenhouse gas emissions must peak over the next 5-10 years, and by 2050 they must have decreased by approximately 50-60% compared to 2000.There are different models for how global emission reductions can be distributed between different regions and countries. Such models depend on political and other standpoints.Projections based on a convergence of the per capita emissions in different countries to the same level by 2050 and for the two-degree target to be achieved with a probability of around 70% indicate that Swedish emissions need to decrease by approximately 20% by 2020 and by 70% by 2050 compared to 2005. The corresponding figures for the EU are approximately 25% and 80% respectively. Net emissions of carbon dioxide from deforestation and international aviation and shipping are not included in these figures.A lower temperature target, such as 1.5 degrees, requires far more comprehensive emission reductions and could be unachievable without a temporary overshooting of the required long-term stabilisation of greenhouse gas levels in the atmosphere.For a 1.5-degree target to be achieved without such an overshoot and with a probability of approximately 50%, global emissions need to start decreasing within the next few years. By the year 2050, global emissions must have decreased by 80% compared to 2000. A probability of approximately 70% involves that global emissions are around zero by 2050.Projections based on a convergence of the per capita emissions in different countries to the same level by 2050 and for a 1.5-degree target to be achieved with a probability of around 50%, indicate that Swedish emissions need to decrease by approximately 25% by 2020 and by over 90% by 2050 compared to 2005. The corresponding figures for the EU are approximately 30% and just over 90% respectively. Net emissions of carbon dioxide from deforestation and international aviation and shipping are not included in these figures.There is uncertainty regarding the climate effects under different temperature targets, but it is well-established that climate effects in certain regions, such as the Arctic, could be extensive even if the two-degree target is reached. Reducing global warming reduces the risk of climate effects, but even if the two-degree target is met the sea level will rise, ocean acidification will increase and important impacts on biological diversity can be expected

Anonymous: merry Christmas
Anonymous: hmm
Anonymous: thanks
Anonymous: OK
Anonymous: so what's up
Anonymous: OK
Similar questions