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 CHANGE

Definition: 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.

REFERENCE 1. Future N2O from US agriculture:projecting effects of changing landuse,

agricultural technology, and climate on N2O emissions, Michael J. Scotta,*, Ronald D. Sandsb, Norman J. Rosenbergb, R. C!esar Izaurraldeb

2. Climate Change effects on greenhouse gas emissions from Northern European soils, Denise Wagner

3. 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*, FRANC¸ OISE YOKO ISHIDAw and D ANI E L C . NE P S TA D

4. Climate Change Synthesis Report 2007 5. Climate Change Synthesis Report 2009