Effects of climate change on the emmission of n2o
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Transcript of Effects of climate change on the emmission of n2o
EFFECTS OF CLIMATE CHANGE ON N2O EMISSIONS
Presented By: Aditya Parmar Zoiab Hassan
Bernard
Climate Change • Definition • Causes and Effects
N2O• Global Warming Potential • Trends• Causes
Emissions • Porcess and Factors • Findings • Conclusion
CONTENTS
CLIMATE CHANGEDefinition: Climate change refers to a change in the state of the climate that can be
identified (e.g. using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. It refers to any change in climate over time, whether due to natural variability or as a result of human activity.
This usage differs from that in the United Nations Framework Convention on Climate Change (UNFCCC), where climate change refers to a change of climate that is attributed directly or indirectly by human activity.
Source: Climate Change 2007: Synthesis Report
CLIMATE CHANGE
Source: Climate Change 2007: Synthesis Report
CLIMATE CHANGE
Source: Climate Change Global Risk, Challenges and Decisions COPENHAGEN 2009: Synthesis Report
N2O
Green House Gas Life Time Global Warming Potential ( For two time horizons)
Carbon dioxide Variable 1 1
Nitrous Oxide 120 years 280(20 years)
310(100 years)
Source: United Nations Framework Convention on Climate Change
Source: Wikipedia
Source: Climate Change Global Risk, Challenges and Decisions COPENHAGEN 2009: Synthesis Report
N2O
Source: Climate Change 2007: Synthesis Report
EMISSIONS
1. Nitrification: Aerobic process in which ammonium (NH4) is oxidised to
nitrate (NO3) (Davidson et al., 1993). Some of the NH4 is channelled into production of NO and N2O (Poth and Focht, 1985).
2. Denitrification: It is the anaerobic reduction of NO3 to N2O and N2 (Davidson
and A., 1993), through a wide range of bacteria, which are able to denitrify. The largest rates of N2O emission tend to be associated with denitrification (Skiba and Smith, 2000).
Influencing Factor
s
Temperature
Soil Moisture
Nitrogen Availability
& Deposition
Soil Type & Acidity
Microbial Activity
Land Use
FINDINGS - TEMPERATURE
A laboratory investigation was performed to measure N2O fluxes from 13 Northern European soils with different land use types (cropland, forest, grassland and wetland).
The global temperature will rise up
between 1.5 and 4.5°C, especially in the northern altitudes in comparison to the rest of Europe (IPCC, 2007).
Source: Climate Change effects on greenhouse gas emissions from Northern European soils - Universität Wien 2009,
Most Sites emission increased under increasing temperature
conditions.
FINDINGS - TEMPERATURE The Pearson rank correlation demonstrates that at nine sites soil temperature has apositive influence on N2O emissions with an r ranging from 0.15 to 0.45 at BE-Vieand DK-Ris Only the two sites IE-Dri and RU-Fyo soil temperature has anegative influence on the N2O fluxes. At the two forest sites FI-Sod and UK-Gri nosignificant effect could be seen.
Statistical Correlation Test was conducted : Pearson or Spearman : correlation factors (r), significance level (p), and number of observations (n), between N2O fluxes and the independent factor soil temperature (Temp. [°C ] from 5-20°C)
Source: Climate Change effects on greenhouse gas emissions from Northern European soils - Universität Wien 2009,
An increase in temperature leads to an increase in the size of anaerobic zones and thusleads to an increase in the rate of denitrification (Smith et al., 2003).
FINDINGS - TEMPERATURE
Source: Future N2O from US agriculture: projecting effects of changing land use, agricultural technology, and climate on N2O emissions 2002
Another interesting study was done by using simulated technology and market relationships governing nitrous oxide (N2O) emissions from US agriculture for the purpose of conducting policy-sensitive emissions modelling of this greenhouse gas.
FINDINGS – SOIL MOISTURE
Source: Climate Change effects on greenhouse gas emissions from Northern European soils - Universität Wien 2009,
The precipitation during summer will rise in the northern higher latitudes of Europe in comparison to the rest of the Europe (IPCC, 2007).
The same study of the 13 sites of Northern Europe was extended to the change in WFPS ( water filled pore space )
For most of the sites emission increased with the
increase in WFPS
FINDINGS – SOIL MOISTURE We observed a positive correlation of N2O with soil moisture for 11 from 13 sites. The mean correlation factor for N2O emissions ranged from 0.15, at NLCab, up to 0.46, at DK-LVa site, (Table 7). One arable soil (BE-Lon) and one forest site (BE-Bra) showed no significant correlation between N2O increase and increasing soil moisture.
As soil WFPS increases, diffusion of O2 into soil aggregates will decrease and hence Climate Change effects on greenhouse gas emissions from Northern European soils much of the soil will become anaerobic. This causes increased N2O emissions by denitrification (Dobbie and Smith, 2001).
Source: Climate Change effects on greenhouse gas emissions from Northern European soils - Universität Wien 2009,
FINDINGS – SOIL MOISTURE
Another interesting study was done in Amazon Basin. Where the climate change predictions are that regional climate may become drier as a result of less recirculation of water between the deforested biosphere and the atmosphere (Shukla et al., 1990; Nobre et al., 1991; Costa & Foley, 2000;Werth & Avisar, 2002).
Monthly precipitation at the study site for 1999–2002
The shaded regions show the periods when the throughfall exclusion panels were in place.
Source: Effects of an experimental drought on soil emissions of carbon dioxide, methane, nitrous oxide, and nitric oxide in a moist tropical forest E R IC A. DAV IDSON et al.
FINDINGS – SOIL MOISTURE
Source: Effects of an experimental drought on soil emissions of carbon dioxide, methane, nitrous oxide, and nitric oxide in a moist tropical forest E R IC A. DAV IDSON et al.
For N2O, the annual emissions from the exclusionplot were about half those of the control plot, and this is a statistically significant effect of the treatment.
FINDINGS – SOIL MOISTURE
Source: Effects of an experimental drought on soil emissions of carbon dioxide, methane, nitrous oxide, and nitric oxide in a moist tropical forest E R IC A. DAV IDSON et al.
The relationship between volumetric water content of the top 30cm soil with surface fluxes
N2O fluxes were positively correlated with VWC. The ratio of N2O:NO fluxes was also positively correlated with VWC. Similar results have been shown for many sites, where wet conditions favour the more reduced gas, N2O, and dry conditions favour the more oxidized gas, NO (Firestone & Davidson, 1989; Davidson et al., 2000a; Davidson & Verchot, 2000).
CONCLUSIONThe findings has demonstrated that emissions of N2O are sensitive to changing climate.
Driving key factors for GHG exchange are soil temperature and soil moisture.
Results of different fluxes varied significnatly between different land use type.
Without the implementation of improved management of animal waste and synthetic fertilizers it is highly likely that N2O emissions are going to rise with increasing global temperature scenarios.
The exculision manipulation which is similar the reduction of rainfall during the sever drought events, lowered annual N2O emissions significnatly.
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