scholarly journals Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

2013 ◽  
Vol 13 (7) ◽  
pp. 18307-18344
Author(s):  
O. J. Squire ◽  
A. T. Archibald ◽  
D. J. Beerling ◽  
C. N. Hewitt ◽  
J. Lathière ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Anthropogenic Emissions ◽  
Change Scenario ◽  
Dynamic Global Vegetation Model ◽  
The Tropics

Abstract. Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to calculate potential future (2095) changes in isoprene emissions caused by changes in climate, land use, and the inhibition of isoprene emissions by CO2. From the present day (2000) value of 467 Tg C yr-1, we find that the combined impact of these factors causes a net decrease in isoprene emissions of 259Tg C yr-1 (55%) with individual contributions of +78 Tg C yr-1 (climate change), −190 Tg C yr-1 (land use) and −147 Tg C yr-1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present day. At the surface, decreases in ozone of 6–10 ppb are calculated over the oceans and developed northern hemispheric regions due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4–6 ppb are calculated in the continental Tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario consists of cropland expansion which is most pronounced in the Tropics. The Tropics are also where land use change causes the greatest increases in ozone. As such there is potential for increased crop exposure to harmful levels of ozone. However, we find that these ozone increases are still not large enough to raise ozone to such damaging levels.

scholarly journals Influence of future climate and cropland expansion on isoprene emissions and tropospheric ozone

2014 ◽  
Vol 14 (2) ◽  
pp. 1011-1024 ◽  
Author(s):  
O. J. Squire ◽  
A. T. Archibald ◽  
N. L. Abraham ◽  
D. J. Beerling ◽  
C. N. Hewitt ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Anthropogenic Emissions ◽  
Change Scenario ◽  
Dynamic Global Vegetation Model ◽  
The Tropics

Abstract. Over the 21st century, changes in CO2 levels, climate and land use are expected to alter the global distribution of vegetation, leading to changes in trace gas emissions from plants, including, importantly, the emissions of isoprene. This, combined with changes in anthropogenic emissions, has the potential to impact tropospheric ozone levels, which above a certain level are harmful to animals and vegetation. In this study we use a biogenic emissions model following the empirical parameterisation of the MEGAN model, with vegetation distributions calculated by the Sheffield Dynamic Global Vegetation Model (SDGVM) to explore a range of potential future (2095) changes in isoprene emissions caused by changes in climate (including natural land use changes), land use, and the inhibition of isoprene emissions by CO2. From the present-day (2000) value of 467 Tg C yr−1, we find that the combined impact of these factors could cause a net decrease in isoprene emissions of 259 Tg C yr−1 (55%) with individual contributions of +78 Tg C yr−1 (climate change), −190 Tg C yr−1 (land use) and −147 Tg C yr−1 (CO2 inhibition). Using these isoprene emissions and changes in anthropogenic emissions, a series of integrations is conducted with the UM-UKCA chemistry-climate model with the aim of examining changes in ozone over the 21st century. Globally, all combined future changes cause a decrease in the tropospheric ozone burden of 27 Tg (7%) from 379 Tg in the present-day. At the surface, decreases in ozone of 6–10 ppb are calculated over the oceans and developed northern hemispheric regions, due to reduced NOx transport by PAN and reductions in NOx emissions in these areas respectively. Increases of 4–6 ppb are calculated in the continental tropics due to cropland expansion in these regions, increased CO2 inhibition of isoprene emissions, and higher temperatures due to climate change. These effects outweigh the decreases in tropical ozone caused by increased tropical isoprene emissions with climate change. Our land use change scenario consists of cropland expansion, which is most pronounced in the tropics. The tropics are also where land use change causes the greatest increases in ozone. As such there is potential for increased crop exposure to harmful levels of ozone. However, we find that these ozone increases are still not large enough to raise ozone to such damaging levels.

scholarly journals The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6

2016 ◽  
Vol 9 (9) ◽  
pp. 3461-3482 ◽  
Author(s):  
Brian C. O'Neill ◽  
Claudia Tebaldi ◽  
Detlef P. van Vuuren ◽  
Veronika Eyring ◽  
Pierre Friedlingstein ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
21St Century ◽  
Integrated Assessment ◽  
Climate Model ◽  
Model Intercomparison ◽  
Wide Range ◽  
Scenario Model ◽  
Intercomparison Project

Abstract. Projections of future climate change play a fundamental role in improving understanding of the climate system as well as characterizing societal risks and response options. The Scenario Model Intercomparison Project (ScenarioMIP) is the primary activity within Phase 6 of the Coupled Model Intercomparison Project (CMIP6) that will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. In this paper, we describe ScenarioMIP's objectives, experimental design, and its relation to other activities within CMIP6. The ScenarioMIP design is one component of a larger scenario process that aims to facilitate a wide range of integrated studies across the climate science, integrated assessment modeling, and impacts, adaptation, and vulnerability communities, and will form an important part of the evidence base in the forthcoming Intergovernmental Panel on Climate Change (IPCC) assessments. At the same time, it will provide the basis for investigating a number of targeted science and policy questions that are especially relevant to scenario-based analysis, including the role of specific forcings such as land use and aerosols, the effect of a peak and decline in forcing, the consequences of scenarios that limit warming to below 2 °C, the relative contributions to uncertainty from scenarios, climate models, and internal variability, and long-term climate system outcomes beyond the 21st century. To serve this wide range of scientific communities and address these questions, a design has been identified consisting of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions, divided into two tiers defined by relative priority. Some of these scenarios will also provide a basis for variants planned to be run in other CMIP6-Endorsed MIPs to investigate questions related to specific forcings. Harmonized, spatially explicit emissions and land use scenarios generated with integrated assessment models will be provided to participating climate modeling groups by late 2016, with the climate model simulations run within the 2017–2018 time frame, and output from the climate model projections made available and analyses performed over the 2018–2020 period.

scholarly journals Assessment of impacts of agricultural and climate change scenarios on watershed water quantity and quality, and crop production

2016 ◽  
Author(s):  
Awoke D. Teshager ◽  
Philip W. Gassman ◽  
Justin T. Schoof ◽  
Silvia Secchi
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Agricultural Land ◽  
Agricultural Landscapes ◽  
Water Quantity ◽  
Agricultural Land Use ◽  
Water Quantity And Quality

Abstract. Modeling impacts of agricultural scenarios and climate change on surface water quantity and quality provides useful information for planning effective water, environmental, and land use policies. Despite the significant impacts of agriculture on water quantity and quality, limited literature exists that describes the combined impacts of agricultural land use change and climate change on future bioenergy crop yields and watershed hydrology. In this study, the Soil and Water Assessment Tool (SWAT) eco-hydrological model was used to model the combined impacts of five agricultural land use change scenarios and three downscaled climate pathways (representative concentration pathways, RCPs) that were created from an ensemble of eight atmosphere-ocean general circulation models (AOGCMs). These scenarios were implemented in a well calibrated SWAT model for the Raccoon River watershed (RRW) located in western Iowa. The scenarios were executed for the historical baseline, early-century, mid-century, and late-century periods. The results indicate that historical and more corn intensive agricultural scenarios with higher CO2 emissions consistently result in more water in the streams and greater water quality problems, especially late in the 21st century. Planting more switchgrass, on the other hand, results in less water in the streams and water quality improvements relative to the baseline. For all given agricultural landscapes simulated, all flow, sediment and nutrient outputs increase from early-to-late century periods for the RCP4.5 and RCP8.5 climate scenarios. We also find that corn and switchgrass yields are negatively impacted under RCP4.5 and RCP8.5 scenarios in the mid and late 21st century.

Impact of Climate and Land Use Changes on the Flood Hazard of the Middle Brahmaputra Reach, India

2012 ◽  
Vol 7 (5) ◽  
pp. 573-581 ◽  
Author(s):  
Subashisa Dutta ◽  
◽  
Shyamal Ghosh
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Land Cover ◽  
Climate Change Scenario ◽  
Hydrological Model ◽  
Flood Hazard ◽  
Baseline Period ◽  
Change Scenario ◽  
Flood Characteristics

Being the highest specific discharge river in the world, the Brahmaputra has a large floodplain area of 700 km in length in its middle reaches falling in the high flood vulnerability category. Floods generated in upland Himalayan catchments are mainly controlled by land use and land cover, storm characteristics, and vegetation dynamics. Floods propagate through a floodplain region consisting of wetlands, paddy agriculture, and wide braided river reaches with natural constraint points (nodals) that make the reaches more vulnerable to flood hazards. In this study, a macroscale distributed hydrological model was used to obtain the flood characteristics of the reaches. A hydrological model with spatially distributed input parameters and meteorological data was simulated at (1 km × 1 km) spatial grids to estimate flood hydrographs at the main river and itsmajor tributaries. Aftermodel validation, “best guess” land use change scenarios were used to estimate potential changes in flood characteristics. Results show that at the middle reaches of the Brahmaputra, peak discharge increases by a maximum of 9% for land use change scenarios. The same model with bias-corrected climatological data from a regional climate model (RCM) simulation (PRECIS) was used to obtain future changes in flood generation and its propagation through the basin in the projected climatological scenario. Changes in flood characteristics with reference to the baseline period show that the average duration of flood waves will increase from 15.2 days in the baseline period (1961-1990) to 19.3 days in the future (2071-2100). Peak discharge will increase by an average of 21% in the future in the projected climate change scenario. After statistics on changes of flood characteristics in the projected climate change scenario (2071-2100) were obtained, a 2-dimensional hydrodynamic model was used to obtain flood inundation and velocity distribution on the floodplain. Distribution of velocity and inundation depth was spatially analyzed to obtain flood hazard zones in the projected climate change scenario. Results show that spatial variation in flood hazard zones will be significantly altered in the projected climate change scenario compared to land use/land cover changes.

scholarly journals Tropospheric ozone changes, radiative forcing and attribution to emissions in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

2013 ◽  
Vol 13 (6) ◽  
pp. 3063-3085 ◽  
Author(s):  
D. S. Stevenson ◽  
P. J. Young ◽  
V. Naik ◽  
J.-F. Lamarque ◽  
D. T. Shindell ◽  
...  
Keyword(s):  
Climate Change ◽  
Atmospheric Chemistry ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Anthropogenic Emissions ◽  
Model Intercomparison ◽  
A Value ◽  
Intercomparison Project ◽  
Column Ozone ◽  
Global Mean

Abstract. Ozone (O3) from 17 atmospheric chemistry models taking part in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) has been used to calculate tropospheric ozone radiative forcings (RFs). All models applied a common set of anthropogenic emissions, which are better constrained for the present-day than the past. Future anthropogenic emissions follow the four Representative Concentration Pathway (RCP) scenarios, which define a relatively narrow range of possible air pollution emissions. We calculate a value for the pre-industrial (1750) to present-day (2010) tropospheric ozone RF of 410 mW m−2. The model range of pre-industrial to present-day changes in O3 produces a spread (±1 standard deviation) in RFs of ±17%. Three different radiation schemes were used – we find differences in RFs between schemes (for the same ozone fields) of ±10%. Applying two different tropopause definitions gives differences in RFs of ±3%. Given additional (unquantified) uncertainties associated with emissions, climate-chemistry interactions and land-use change, we estimate an overall uncertainty of ±30% for the tropospheric ozone RF. Experiments carried out by a subset of six models attribute tropospheric ozone RF to increased emissions of methane (44±12%), nitrogen oxides (31 ± 9%), carbon monoxide (15 ± 3%) and non-methane volatile organic compounds (9 ± 2%); earlier studies attributed more of the tropospheric ozone RF to methane and less to nitrogen oxides. Normalising RFs to changes in tropospheric column ozone, we find a global mean normalised RF of 42 mW m−2 DU−1, a value similar to previous work. Using normalised RFs and future tropospheric column ozone projections we calculate future tropospheric ozone RFs (mW m−2; relative to 1750) for the four future scenarios (RCP2.6, RCP4.5, RCP6.0 and RCP8.5) of 350, 420, 370 and 460 (in 2030), and 200, 300, 280 and 600 (in 2100). Models show some coherent responses of ozone to climate change: decreases in the tropical lower troposphere, associated with increases in water vapour; and increases in the sub-tropical to mid-latitude upper troposphere, associated with increases in lightning and stratosphere-to-troposphere transport. Climate change has relatively small impacts on global mean tropospheric ozone RF.

scholarly journals Impact of climate change on tropospheric ozone and its global budgets

2008 ◽  
Vol 8 (2) ◽  
pp. 369-387 ◽  
Author(s):  
G. Zeng ◽  
J. A. Pyle ◽  
P. J. Young
Keyword(s):  
Climate Change ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Surface Ozone ◽  
Lower Troposphere ◽  
Ozone Production ◽  
Anthropogenic Emissions ◽  
Free Troposphere ◽  
Tropical Ocean ◽  
Ozone Levels

Abstract. We present the chemistry-climate model UMCAM in which a relatively detailed tropospheric chemical module has been incorporated into the UK Met Office's Unified Model version 4.5. We obtain good agreements between the modelled ozone/nitrogen species and a range of observations including surface ozone measurements, ozone sonde data, and some aircraft campaigns. Four 2100 calculations assess model responses to projected changes of anthropogenic emissions (SRES A2), climate change (due to doubling CO2), and idealised climate change-associated changes in biogenic emissions (i.e. 50% increase of isoprene emission and doubling emissions of soil-NOx). The global tropospheric ozone burden increases significantly for all the 2100 A2 simulations, with the largest response caused by the increase of anthropogenic emissions. Climate change has diverse impacts on O3 and its budgets through changes in circulation and meteorological variables. Increased water vapour causes a substantial ozone reduction especially in the tropical lower troposphere (>10 ppbv reduction over the tropical ocean). On the other hand, an enhanced stratosphere-troposphere exchange of ozone, which increases by 80% due to doubling CO2, contributes to ozone increases in the extratropical free troposphere which subsequently propagate to the surface. Projected higher temperatures favour ozone chemical production and PAN decomposition which lead to high surface ozone levels in certain regions. Enhanced convection transports ozone precursors more rapidly out of the boundary layer resulting in an increase of ozone production in the free troposphere. Lightning-produced NOx increases by about 22% in the doubled CO2 climate and contributes to ozone production. The response to the increase of isoprene emissions shows that the change of ozone is largely determined by background NOx levels: high NOx environment increases ozone production; isoprene emitting regions with low NOx levels see local ozone decreases, and increase of ozone levels in the remote region due to the influence of PAN chemistry. The calculated ozone changes in response to a 50% increase of isoprene emissions are in the range of between −8 ppbv to 6 ppbv. Doubling soil-NOx emissions will increase tropospheric ozone considerably, with up to 5 ppbv in source regions.

scholarly journals Impact of climate change on tropospheric ozone and its global budgets

2007 ◽  
Vol 7 (4) ◽  
pp. 11141-11189 ◽  
Author(s):  
G. Zeng ◽  
J. A. Pyle ◽  
P. J. Young
Keyword(s):  
Climate Change ◽  
Tropospheric Ozone ◽  
Climate Model ◽  
Surface Ozone ◽  
Lower Troposphere ◽  
Ozone Production ◽  
Anthropogenic Emissions ◽  
Free Troposphere ◽  
Tropical Ocean ◽  
Ozone Levels

Abstract. We present the chemistry-climate model UM_CAM in which a relatively detailed tropospheric chemical module has been incorporated into the UK Met Office's Unified Model version 4.5. We obtain good agreements between the modelled ozone/nitrogen species and a range of observations including surface ozone measurements, ozone sonde data, and some aircraft campaigns. Four 2100 calculations assess model responses to projected changes of anthropogenic emissions (SRES A2), climate change (due to doubling CO2), and idealised climate change associated changes in biogenic emissions (i.e. 50% increase of isoprene emission and doubling emissions of soil-NOx). The global tropospheric ozone burden increases significantly for all the 2100 A2 simulations, with the largest response caused by the increase of anthropogenic emissions. Climate change has diverse impacts on O3 and its budgets through changes in circulation and meteorological variables. Increased water vapour causes a substantial ozone reduction especially in the tropical lower troposphere (>10 ppbv reduction over the tropical ocean). On the other hand, an enhanced stratosphere-troposphere exchange of ozone, which increases by 80% due to doubling CO2, contributes to ozone increases in the extratropical free troposphere which subsequently propagate to the surface. Projected higher temperatures favour ozone chemical production and PAN decomposition which lead to high surface ozone levels in certain regions. Enhanced convection transports ozone precursors more rapidly out of the boundary layer resulting in an increase of ozone production in the free troposphere. Lightning-produced NOx increases by about 22% in the doubled CO2 climate and contributes to ozone production. The response to the increase of isoprene emissions shows that the change of ozone is largely determined by background NOx levels: high NOx environment increases ozone production; isoprene emitting regions with low NOx levels see local ozone decreases, and increase of ozone levels in the remote region due to the influence of PAN chemistry. The calculated ozone changes in response to a 50% increase of isoprene emissions are in the range of between –8 ppbv to 6 ppbv. Doubling soil-NOx emissions will increase tropospheric ozone considerably, with up to 5 ppbv in source regions.

scholarly journals Assessment of impacts of agricultural and climate change scenarios on watershed water quantity and quality, and crop production

2016 ◽  
Vol 20 (8) ◽  
pp. 3325-3342 ◽  
Author(s):  
Awoke D. Teshager ◽  
Philip W. Gassman ◽  
Justin T. Schoof ◽  
Silvia Secchi
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
21St Century ◽  
Agricultural Land ◽  
Agricultural Landscapes ◽  
Water Quantity ◽  
Agricultural Land Use ◽  
Water Quantity And Quality

Abstract. Modeling impacts of agricultural scenarios and climate change on surface water quantity and quality provides useful information for planning effective water, environmental and land use policies. Despite the significant impacts of agriculture on water quantity and quality, limited literature exists that describes the combined impacts of agricultural land use change and climate change on future bioenergy crop yields and watershed hydrology. In this study, the soil and water assessment tool (SWAT) eco-hydrological model was used to model the combined impacts of five agricultural land use change scenarios and three downscaled climate pathways (representative concentration pathways, RCPs) that were created from an ensemble of eight atmosphere–ocean general circulation models (AOGCMs). These scenarios were implemented in a well-calibrated SWAT model for the intensively farmed and tiled Raccoon River watershed (RRW) located in western Iowa. The scenarios were executed for the historical baseline, early century, mid-century and late century periods. The results indicate that historical and more corn intensive agricultural scenarios with higher CO2 emissions consistently result in more water in the streams and greater water quality problems, especially late in the 21st century. Planting more switchgrass, on the other hand, results in less water in the streams and water quality improvements relative to the baseline. For all given agricultural landscapes simulated, all flow, sediment and nutrient outputs increase from early-to-late century periods for the RCP4.5 and RCP8.5 climate scenarios. We also find that corn and switchgrass yields are negatively impacted under RCP4.5 and RCP8.5 scenarios in the mid- and late 21st century.

SOL40: forty years of simulations under a climate and land use change scenario 

2021 ◽  
Author(s):  
Alessandro Ceppi ◽  
Enrico Gambini ◽  
Gabriele Lombardi ◽  
Giovanni Ravazzani ◽  
Marco Mancini
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
Curve Number ◽  
Change Scenario ◽  
Catchment Scale ◽  
Physically Based ◽  
Anthropogenic Development ◽  
Meteoric Precipitation ◽  
The Impact

<p>Nowadays, one major issue concerns the land-use change due to urban developments that alters the basin response to meteorological events. With less storage capacity and more rapid runoff, urban river basins rise more quickly during storms and have higher peak discharge rates than rural catchments.</p><p>An exemplary case of this situation is the city of Milan and its whole territory that extends towards north that collects meteoric precipitation, through the Seveso, Olona and Lambro (SOL) rivers plus a number of minor tributaries for a total drainage surface of about 1300 km<sup>2</sup>.</p><p>In order to assess the impact of anthropogenic development on urban catchment scale hydrology, a reanalysis of 40 years of simulations has been carried out with the Curve Number (CN) map based on current land use, and compared to simulations with the CN maps derived using past land use.</p><p>A coupled hydro-meteorological system which comprises the physically based rainfall-runoff hydrological model FEST-WB, developed by the Politecnico di Milano and the ERA5-Land hourly dataset from 1981 to present, provided by ECMWF under the framework of Copernicus Climate Change Service Programme has been built.</p><p>The study (named as SOL40) exactly analyses 40-years trends of the main meteorological (air temperature, precipitation, etc.) and hydrological variables (soil moisture, evapotranspiration and runoff) over the SOL area, and try to quantify and separate the impact of land use change from the climate change scenario.</p>

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