scholarly journals CAMBIAMENTI CLIMATICI: EVIDENZE SCIENTIFICHE, RISCHI ED OPPORTUNITÀ DI MITIGAZIONE

Author(s):  
Filippo Giorgi

This contribution presents the various pieces of evidence which bring the scientific community to conclude that global warming is happening and it is mostly due to anthropogenic emissions of greenhouse gases, mainly carbon dioxide and methane, deriving from the use of fossil fuels and some intensive agricultural practices. The main climatic changes associated with global warming are then discussed, along with the main model-derived future climate scenarios and the impacts that climate change can have on different socioeconomic sectors. Finally, the response policies to global warming are described, and in particular the concepts of adaptation and mitigaziotn (reduction of greenhouse gas emissions).

Author(s):  
Shamshad Akhtar ◽  
Muhammad Rafique Dhanani

Climate change is not the new phenomenon. The palaeo-climatic studies reveal that during the Pleistocene and Holocene periods several warm and cold periods occurred, resulted change of sea level and change in climatic processes like rise and fall of global average temperature and rainfall. The last medieval warm period was observed from 950 to 1350 AD, followed by the little Ice Age from 1400 to 1900 AD. Occurrence of these climatic changes and their impacts are considered due to natural processes that are geological and astronomical. In 1970s environmentalists and some climate scientists pointed that earth’s average temperature is rising linked with the anthropogenic causes of global warming and emission of carbon dioxide through fossil fuels. In late 1980s the problem was discussed in politics and media. To examine and monitor the global rise of temperature and its impacts due to the emission of carbon dioxide an organization of Intergovernmental Panel on Climate Change (IPCC) was created in 1988 by United Nations Environment Programme (UNEP). The IPCC released several reports based upon anthropogenic causes of climate change and their impacts. According to IPCC, 2007 report on climate change during the last 100 years the earth’s average temperature has increased up to 0.6 degree Celsius and if emission of greenhouse gases particularly carbon dioxide continues to rise, global temperature will rise up to 5.8 degrees Celsius by the end of 2100 AD. Similarly as a result of this threat of global warming, glaciers will disappear even from Antarctica and Arctic sea will open for navigation throughout the year. Many islands and coastal cities will submerge as a result of sea level rise. In 2004 Canadian Broadcasting T.V presented a documentary with the name “ The doomsday called off” in which leading climate scientists, astrophysicist and geophysicist presented evidences that science of global warming presented by IPCC scientists is incomplete and incorrect based upon computer models and stimulations which are deliberately exaggerated. Many climate scientists have shown disassociation with the IPCC views and speculations on the basis of its doubtful manipulated and exaggerated figures of global warming and some consider it a climate scam. Since then debate between UN pro man-made global warming scientists and anti-man-made global warming climate scientists continue.


2021 ◽  
pp. 12-25
Author(s):  
Mark Maslin

‘History of climate change’ traces the history of climate change and the evidence that supports it. The science of climate change started in 1856 with experiments by Eunice Newton Foote demonstrating the greenhouse effect of carbon dioxide. The essential science of climate change was there in the late 1950s, but it was not taken seriously until the late 1980s. Why was there a delay between the science of global warming being accepted in the late 1950s and the realization by those outside the scientific community of the true threat of global warming at the beginning of the 21st century? The key reasons for this delay were the lack of increase in global temperatures and the lack of global environmental awareness. What is the importance of the rise of the global environmental social movement and the new wave of protest and optimism of the last few years?


Author(s):  
Judith S. Weis

What causes global warming or climate change? The burning of fossil fuels emits carbon dioxide into the atmosphere, which results in the greenhouse effect—less heat can be re-radiated away from the earth, thus raising the temperature of the atmosphere and ocean. In the past...


2019 ◽  
Vol 11 (4) ◽  
pp. 1675-1710 ◽  
Author(s):  
Robbie M. Andrew

Abstract. Global production of cement has grown very rapidly in recent years, and, after fossil fuels and land-use change, it is the third-largest source of anthropogenic emissions of carbon dioxide. The availability of the required data for estimating emissions from global cement production is poor, and it has been recognised that some global estimates are significantly inflated. This article assembles a large variety of available datasets, prioritising official data and emission factors, including estimates submitted to the UN Framework Convention on Climate Change (UNFCCC), plus new estimates for China and India, to present a new analysis of global process emissions from cement production. Global process emissions in 2018 were 1.50±0.12 Gt CO2, equivalent to about 4 % of emissions from fossil fuels. Cumulative emissions from 1928 to 2018 were 38.3±2.4 Gt CO2, 71 % of which have occurred since 1990. The data associated with this article can be found at https://doi.org/10.5281/zenodo.831454 (Andrew, 2019).


1991 ◽  
Vol 20 (2) ◽  
pp. 151-163
Author(s):  
Harry M. Kaiser

Without a doubt, climate change will be one of the most important environmental topics of the 1990s and will be high on the research agendas of many scientific disciplines in years ahead. While not yet universally accepted, it is now widely believed that anthropogenic emissions of carbon dioxide and other “greenhouse” gases have the potential to substantially warm climates worldwide. Although there is no consensus on the timing and magnitude of global warming, current climate models predict an average increase of 2.8°C to 5.2°C in the earth's temperature over the next century (Karl, Diaz, and Barnett). Changes in regional temperature and precipitation will likely accompany the global warming, but there is even less scientific agreement on the magnitude of these changes.


2016 ◽  
Vol 4 (2) ◽  
pp. 1 ◽  
Author(s):  
Jan Erik Lane

The implementation process of the global accord on climate change has to start now in order to be implementable. The decentralized process if implementation should take the lessons from the theory of policy implementation into account (Pressman & Wildavsky, 1984; Wildavsky, 1987). The dependency upon various forms of coal (wood, stone) and fossil fuels is so large in the Third World that only massive financial assistance from the First World can mean a difference for the COP21 objectives. And many advanced countries (except Uruguay) also need to make great changes to comply with COP21.


2015 ◽  
Vol 28 (18) ◽  
pp. 7327-7346 ◽  
Author(s):  
Xiuquan Wang ◽  
Guohe Huang ◽  
Jinliang Liu ◽  
Zhong Li ◽  
Shan Zhao

Abstract In this study, high-resolution climate projections over Ontario, Canada, are developed through an ensemble modeling approach to provide reliable and ready-to-use climate scenarios for assessing plausible effects of future climatic changes at local scales. The Providing Regional Climates for Impacts Studies (PRECIS) regional modeling system is adopted to conduct ensemble simulations in a continuous run from 1950 to 2099, driven by the boundary conditions from a HadCM3-based perturbed physics ensemble. Simulations of temperature and precipitation for the baseline period are first compared to the observed values to validate the performance of the ensemble in capturing the current climatology over Ontario. Future projections for the 2030s, 2050s, and 2080s are then analyzed to help understand plausible changes in its local climate in response to global warming. The analysis indicates that there is likely to be an obvious warming trend with time over the entire province. The increase in average temperature is likely to be varying within [2.6, 2.7]°C in the 2030s, [4.0, 4.7]°C in the 2050s, and [5.9, 7.4]°C in the 2080s. Likewise, the annual total precipitation is projected to increase by [4.5, 7.1]% in the 2030s, [4.6, 10.2]% in the 2050s, and [3.2, 17.5]% in the 2080s. Furthermore, projections of rainfall intensity–duration–frequency (IDF) curves are developed to help understand the effects of global warming on extreme precipitation events. The results suggest that there is likely to be an overall increase in the intensity of rainfall storms. Finally, a data portal named Ontario Climate Change Data Portal (CCDP) is developed to ensure decision-makers and impact researchers have easy and intuitive access to the refined regional climate change scenarios.


2020 ◽  
Vol 10 (7) ◽  
pp. 2330
Author(s):  
Trinity S. Senda ◽  
Gregory A. Kiker ◽  
Patricia Masikati ◽  
Albert Chirima ◽  
Johan van Niekerk

Smallholder farmers in semi-arid areas depend on both cropping and livestock as the main sources of livelihoods. Rangeland productivity varies on both spatial and temporal scales and provides the major source of feed for livestock. Rangeland productivity is expected to decline with climate change thereby reducing livestock feed availability and consequently livelihoods that depend on livestock. This study was carried out to assess the impacts of climate change on rangeland productivity and consequently livestock population dynamics using a 30-year simulation modeling approach. The climate scenarios used in the simulations are built from the localized predictions by General Circulation Models (GCMs). The primary climate variables under consideration are rainfall (+/−7% change), carbon dioxide (CO2 up to 650 ppm) and temperature (+4 °C change). This was done by applying the SAVANNA ecosystem model which simulates rangeland processes and demographic responses of herbivores on a temporal and spatial scale using a weekly internal time step and monthly spatial and temporal outputs. The results show that rainfall levels of less than 600 mm/year have the largest negative effect on herbaceous biomass production. The amount of biomass from the woody layer does not change much during the year. The carbon dioxide (CO2) effects are more influential on the tree and shrub layers (C3 plants) than the herbaceous layer (C4 grasses). The CO2 effect was more dominant than the effects of rainfall and temperature. In the baseline simulations, the shrub plant layer increased significantly over 30 years while there is a three-fold increase in the woody plant layer (trees and shrubs) where biomass increased from a 1980 production to that of 2010. The biomass of the herbaceous layer was stable over the historical period (1980 to 2010) with values fluctuating between 200 and 400 g/m2. Grass green biomass has a variable distribution where most production occurred in the fields and cleared areas while lower levels of production were found in the forested areas. The spatial distribution of shrub green biomass was less directly linked to yearly rainfall. Shrub biomass was mostly found in forested areas, and it showed a steady increase in production. Cattle, donkey, and goat populations rose slowly from 1980 but the rise was disrupted by a dry period during the late 1980s to the early 1990s causing a decline in all populations primarily due to grass unavailability. The populations of cattle goats and donkeys started to rise again from 1995 onwards due to improvements in rainfall. Cattle and donkey populations were rising faster than that of goats while sheep population was not changing much for most of the simulation period, otherwise they declined significantly during the drought of 2002. Similar changes in simulated grass biomass (g/m2) were observed in almost all climate scenarios, except for the peak and low years. The livestock population simulation showed few variations in livestock population under all scenarios. The main conclusion from the study is that CO2 effects on rangeland productivity are much more dominant than the localized effects of rainfall and temperature. This has implications of favoring the growth of the tree and shrub layers over herbaceous layer, which meant that in the long run, the species that are able to use tree and shrub layers may be kept as a livelihood source as they will have a feed source.


2020 ◽  
Vol 10 (6) ◽  
pp. 2014 ◽  
Author(s):  
Mariano Pierantozzi ◽  
Sebastiano Tomassetti ◽  
Giovanni Di Nicola

The most commonly used refrigerants are potent greenhouse gasses that can contribute to climate change. Hydro-Fluoro-Olefins are low Global Warming Potential fluids. A summary of our experimental research activity on the thermodynamic properties of two environmentally friendly Hydro-Fluoro-Olefins, namely R1234yf and R1234ze(E), is reported. In particular, the measurements were performed with an isochoric apparatus and the apparatus specifically built to reach temperatures down to about 100 K. The data elaboration confirms the validity of the choice and that R1234yf and R1234ze(E) can be adopted in many domestic applications. Moreover, considering the reduction of the flammability issues of R1234yf and R1234ze(E), the properties of binary systems containing these fluids and carbon dioxide were analyzed. The presented mixtures could be very interesting for low-temperature applications such as cascade cycles.


Nanoscale ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 2507-2514 ◽  
Author(s):  
Yipeng Bao ◽  
Jin Wang ◽  
Qi Wang ◽  
Xiaofeng Cui ◽  
Ran Long ◽  
...  

Harvesting solar energy to convert carbon dioxide (CO2) into fossil fuels shows great promise to solve the current global problems of energy crisis and climate change.


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