Bhawan Singh

Impacts of a Ghg-Induced Climate Change on Crop Yields: Effects of Acceleration in Maturation, Moisture Stress and Optimal Temperature

The present study involves using the Canadian Climate Centre (CCC) climate change scenario to evaluate the impacts of a CO2-induced climate change on agriculture in Québec and vicinity. Climate change using the CCC General Circulation Model (GCM) data are fed into a crop model (FAO) so as to gauge the changes in agroclimatic factors such as growing season length and growing degree days, and subsequently potential yield changes for a variety of cereal (C3 and C4), leguminous, oleaginous, vegetable and special crops, for twelve major agricultural regions in southern Québec. Our results show that depending upon the agricultural zone and crop type, yields may increase (ex. corn and sorghum by 20%) or decrease (ex. wheat and soybean by 20 to 30%). Also, these crop yield changes appear to be related to acceleration in maturation rates, mainly to change in moisture stress and to shifts in optimal thermal growth conditions. These possible shifts in agricultural production potentials would solicit the formulation of appropriate adaptation strategies.

Climate-related global changes in the southern Caribbean: Trinidad and Tobago

Abstract A climate change deriving from the atmospheric build up of greenhouse gases (GHG) is supposed to become evident by the middle of the next century. This GHG-induced climate change would supposedly lead to a global warming of about 2 to 4°C and a rise in mean sea level of about 60 cm towards the end of the next century. This study focuses on the field measurements and interpretations of a number of, supposedly, climate-driven regional changes, including shifts in climate and hydrology, coastal erosion and sedimentation, salinisation of coastal aquifers and estuaries, and also coral bleaching, in Trinidad and Tobago, in the southern Caribbean. The results show significant changes and shifts in temperature and rainfall, severe coastal erosion, approaching 2 to 4 m per year for certain beaches, appreciable salinisation of a number of coastal aquifers and an estuary along the Caroni swamp, in Trinidad, and what appears to be partial coral bleaching, at the Culloden Reef in Tobago. These field-observed regional changes may conceivably be interpreted as early signals of a GHG-induced climate change. However, in view of the uncertainty surrounding GHG-induced climate change and sea level rise and the limitations of our data, especially the length of record, caution must be exercised in the interpretation of these results.

Climate changes in the greater and southern Caribbean

A climate change resulting from recent increases in the atmospheric greenhouse gases (GHGs) is supposed to occur sometime in the middle of the next century. This climate change induced by GHGs would be caused by radiative forcing through the greenhouse effect and would lead to global warming and eventually to sea-level rise. This paper presents a climate change scenario for the greater Caribbean as simulated by the Canadian Climate Centre (CCC) general circulation model (GCM). The CCC GCM projects a GHG induced temperature increase of about 2°C and more extreme rainfall conditions for the greater Caribbean. The climate records of temperature, rainfall and cloudiness for several stations on the island of Trinidad are then examined in an attempt to detect GHG climate change signals. The temperature change to date, close to 1°C, and the fluctuations in rainfall patterns, over the last five decades, seem to be indicative of early greenhouse signals.

The effect of synoptic-scale advection on the performance of the Priestley-Taylor evaporation formula

Measurements of the appropriate parameters for the calculation of the latent heat flux over a black spruce forest in northern Quebec were carried out in August, 1980. Values of the Priestley-Taylor parameter, α, were derived by exploiting the Bowen-ratio-energy-balance (BREB) technique. Derived values of α are then related to synoptic-scale warm air advection, derived from surface synoptic charts and tephigrams of the planetary boundary layer. It is found that when warm air advection is present, α > 1.26, especially when the surface is wet. When advection enhancement is removed, however, values of α approach unity. A new approach to calculating the latent heat flux, when warm air advection is present, is therefore proposed.

Rainfall acidity as related to meteorological parameters in Northern Quebec

Abstract Summer-time rainfalls during 1980 and 1981 were collected at several sites near La Grande, 200 km inland from the James Bay coast, in Northern Quebec. These were analyzed for pH and the concentrations of major ions. Concurrent and prior measurements were also taken or derived for a series of meteorological parameters including 85 Kp level wind speed and direction, 85 Kp level air temperature, vertical air movement, these during and prior to rainfall, precipitation amount, duration and intensity, prior duration of precipitation, precipitation type, boundary layer height, surface pressure and surface pressure change and atmospheric divergence. Results demonstrate that wind speed at 85 Kp level 48–72 h prior to rainfall, wind direction at 85 Kp 72 h prior, air temperature at 85 Kp during rainfall and 60–72 h prior, vertical movement of the atmosphere 24 h prior, boundary layer height, surface pressure and surface pressure change and rainfall amount and duration at the site as well as prior duration of rainfall consistently correlate with the log 10 of major ions in rainfall. Also surface wind direction, precipitation type and the trajectory of air masses do not consistently relate to the pH of rainfall.

The effects of climatic change and C02 fertilisation on agriculture in Québec

Abstract The agricultural sector forms an important part of the economy of Quebec. The risk of global increase of atmospheric CO 2 concentration and associated climatic change and their influence on agriculture need to be assessed. Although many studies have been conducted on the effect of climate change on agriculture in various parts of the world, fewer studies have focused on the combined effects of climatic change and CO 2 fertilisation on agriculture. This study, using the outputs of the Canadian Climate Centre (CCC) general circulation model coupled with the Food and Agricultural Organization (FAO) crop model, attempts to assess the response of agricultural productivity to both direct (or fertilisation) and indirect (or climatic) effects of increased atmospheric CO 2 concentration, for a variety of crops including C 3 and C 4 cereals, legumes, vegetables and special crops grown in Quebec. It appears that Ca cereal (corn and sorghum) crops would benefit by climate change but would be least favoured by CO 2 fertilisation effect.

Potential impacts of a CO2-induced climate change using the GISS scenario on agriculture in Quebec, Canada

This study examines the potential impacts of a climate change resulting from an effective doubling of atmospheric CO2 on the potential and anticipated yields of a variety of agricultural crops including corn, soya, potatoes, wheat, phaseolus beans, sorghum, barley, oats, rapeseed and sunflowers and two horticultural crops namely apples and grapes, for southern Quebec. The GISS climate change scenario is used. Our results show that yields would increase for some crops such as corn, soybeans, potatoes, phaseolus beans and sorghum and would decrease for the cereal and oilseed crops, namely wheat, barley, oats, sunflowers and rapeseed. Production opportunities for apples and grapes are enhanced. Also it would seem that the more northerly regions of Abitibi-Temiscamingue and Lac St-Jean would benefit most, in terms of agriculture, from a CO2-induced climate change.

Influence d'un changement climatique dû à une hausse de gaz à effet de serre sur l'agriculture au quebec

Abstract This study, using a climate change scenario generated by the Canadian Climate Centre (CCC) general circulation model (GCM) examines the impacts of such a climate change on agriculture in s...

Ambient air concentrations of asbestos fibers near the town of Asbestos, Québec.

Ambient air concentrations of asbestos fibers were measured during the period June 20 to August 12, 1980, at three locations; Danville, Asbestos, and Wottenville in the eastern townships of Quebec. Measurements were done with low-volume samplers and measurement periods extended from 3 to 13 days. Fiber counts were done by means of electron microscopy. Results indicate that overall fiber concentrations are related to atmospheric stability and to the direction of the prevailing wind with respect to the source of emission.