Abstract: The aim of the research was an agro-climatologic assessment of the amount of rainfall on a local scale, mainly aimed to identify trends in their changes and a possible rise in their variability over time. In the studies also we wanted to demonstrate the impact of the amount of rainfall in the region of Bydgoszcz on the yield of some crops. Material for the study consists of rainfall measurements, carried out in a stand- ard way in the years 1981-2010 at the Research Station of the University of Technology and Life Sciences in Bydgoszcz. Station is located in the village of Mochle, located approximately 20 km from the city centre (φ=53013’ N, λ=17051’E, h=98.5 m above sea level) in sparsely urbanized and industrialized area. We also used data of the yield of selected crops (potato, barley, corn for grain, legumes), from the production in the region of Kujawy and Pomorze as well as from our own experimental field. It has been shown that the average long-term rainfall during the growing season allows for classifying Bydgoszcz region as the area with the lowest rainfall in Poland. Analyzed rainfalls were characterized by a very high variability in time, resulting in climatic risk of plant growing. The largest temporal variability related to August. However, there was no extension of the time variability of rainfall totals in the period 1996-2010, as compared to the period 1981-1995. The sole significant growth trend during the period 1981-2010 was found in May. It appeared a tendency to a decline in summer rainfall totals (VI-VIII) in the annual rainfall total, which is consistent with the IPCC projections. Rainfall totals had highly signi cant impact on yields of selected crops. The highest correlation coefficients were found in relations crop-rainfall in the months of increased water needs of plants. Better correlations rainfall-crop were found using data from the production scale as compared with the scale of experimental field.

Abstract: This study investigates the use of bioenergy for achieving stringent climate stabilization targets and it analyzes the economic drivers behind the choice of bioenergy technologies. We apply the integrated assessment framework REMIND-MAgPIE to show that bioenergy, particularly if combined with carbon capture and storage (CCS) is a crucial mitigation option with high deployment levels and high technology value. If CCS is available, bioenergy is exclusively used with CCS. We find that the ability of bioenergy to provide negative emissions gives rise to a strong nexus between biomass prices and carbon prices. Ambitious climate policy could result in bioenergy prices of 70 $/GJ (or even 430 $/GJ if bioenergy potential is limited to 100 EJ/year), which indicates a strong demand for bioenergy. For low stabilization scenarios with BECCS availability, we find that the carbon value of biomass tends to exceed its pure energy value. Therefore, the driving factor behind investments into bioenergy conversion capacities for electricity and hydrogen production are the revenues generated from negative emissions, rather than from energy production. However, in REMIND modern bioenergy is predominantly used to produce low-carbon fuels, since the transport sector has significantly fewer low-carbon alternatives to biofuels than the power sector. Since negative emissions increase the amount of permissible emissions from fossil fuels, given a climate target, bioenergy acts as a complement to fossils rather than a substitute. This makes the short-term and long-term deployment of fossil fuels dependent on the long-term availability of BECCS.

Abstract: The water conductivity of arctic zone soils derived in different micro-relief forms was determined. The greatest water conductivity at the 0-5 cm depth for the higher values of water potentials (> -7 kJ m(-3)) was shown by tundra polygons (Brunic-Turbic Cryosol, Arenic) – 904-0.09 cm day(-1), whereas the lowest were exhibited by Turbic Cryosols – 95-0.05 cm day(-1). Between -16 and -100 kJ m(-3), the water conductivity for tundra polygons rapidly decreased to 0.0001 cm day(-1), whereas their decrease for the other forms was much lower and in consequence the values were 0.007, 0.04, and 0.01 cm day(-1) for the mud boils (Turbic Cryosol (Siltic, Skeletic)), cell forms (Turbic Cryosol (Siltic, Skeletic)), and sorted circles (Turbic Cryosol (Skeletic)), respectively. In the 10-15 cm layer, the shape of water conductivity curves for the higher values of water potentials is nearly the same as for the upper layer. Similarly, the water conductivity is the highest -0.2 cm day(-1) for tundra polygons. For the lower water potentials, the differences in water conductivity increase to the decrease of soil water potential. At the lowest potential the water conductivity is the highest for sorted circles -0.02 cm day(-1) and the lowest in tundra polygons -0.00002 cm day(-1).