David W. Kicklighter

Marine Biological Laboratory | MBL · Ecosystems Center

Agricultural decision-making by different interest groups (e.g., farmers, development agents and policy makers) usually takes place on different scales (e.g., plot, landscape and country). Currently, tools to assist decision-making are either dedicated to small-scale management guidance or large-scale assessment, which ignore the cross-scale linkag...

Nitrogen (N) availability exerts strong control on carbon storage in the forests of Northern Eurasia. Here, using a process-based model, we explore how three factors that alter N availability-permafrost degradation, atmospheric N deposition, and the abandonment of agricultural land to forest regrowth (land-use legacy)-affect carbon storage in the r...

The Massachusetts Institute of Technology Integrated Global System Model (IGSM) is designed for analyzing the global environmental changes that may result from anthropogenic causes, quantifying the uncertainties associated with the projected changes, and assessing the costs and environmental effectiveness of proposed policies to mitigate climate ri...

Efforts to estimate the physical and economic impacts of future climate change face substantial challenges. To enrich the currently popular approaches to impact analysis-which involve evaluation of a damage function or multi-model comparisons based on a limited number of standardized scenarios-we propose integrating a geospatially resolved physical...

During the past several decades, the Earth system has changed significantly, especially across Northern Eurasia. Changes in the socio-economic conditions of the larger countries in the region have also resulted in a variety of regional environmental changes that can have global consequences. The Northern Eurasia Future Initiative (NEFI) has been de...

Northern Eurasia is made up of a complex and diverse set of physical, ecological, climatic and human systems, which provide important ecosystem services including the storage of substantial stocks of carbon in its terrestrial ecosystems. At the same time, the region has experienced dramatic climate change, natural disturbances and changes in land m...

In the circumpolar north (45–90°N), permafrost plays an important role in vegetation and carbon (C) dynamics. Permafrost thawing has been accelerated by the warming climate and exerts a positive feedback to climate through increasing soil C release to the atmosphere. To evaluate the influence of permafrost on C dynamics, changes in soil temperature...

Globally, 15.5 million km(2) of land are currently identified as protected areas, which provide society with many ecosystem services including climate-change mitigation. Combining a global database of protected areas, a reconstruction of global land-use history, and a global biogeochemistry model, we estimate that protected areas currently sequeste...

Estimates of the seasonal and interannual exchanges of carbon dioxide (CO2) and methane (CH4) between land ecosystems north of 45°N and the atmosphere are poorly constrained, in part, because of uncertainty in the temporal variability of water-inundated land area. Here we apply a process-based biogeochemistry model to evaluate how interannual chang...

The ecosystems in Northern Eurasia (NE) play an important role in the global water cycle and the climate system. While evapotranspiration (ET) is a critical variable to understand this role, ET over this region remains largely unstudied. Using an improved version of the Terrestrial Ecosystem Model (TEM) with five widely used forcing datasets, we ex...

A quantitative understanding of the rate at which land ecosystems are sequestering or losing carbon at national, regional and state-level scales is needed to develop policies to mitigate climate change. In this study, a new improved historical land-use and land-cover change (LULCC) dataset is developed and combined with a process-based ecosystem mo...

Northern Eurasian ecosystems play an important role in the global climate system. Northern Eurasia (NE) has experienced dramatic climate changes during the last half of the 20th century and to present. To date, how evapotranspiration (ET) and water availability (P–ET, P: precipitation) had changed in response to the climatic change in this region h...

Permafrost thaw and the subsequent mobilization of carbon (C) stored in previously frozen soil organic matter (SOM) have the potential to be a strong positive feedback to climate. As the northern permafrost region experiences as much as a doubling of the rate of warming as the rest of the Earth, the vast amount of C in permafrost soils is vulnerabl...

Climate change will alter ecosystem metabolism and may lead to a redistribution of vegetation and changes in fire regimes in Northern Eurasia over the 21st century. Land management decisions will interact with these climate-driven changes to reshape the region’s landscape. Here we present an assessment of the potential consequences of climate chang...

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has...

Development of regional policies to reduce net emissions of carbon dioxide (CO2) would benefit from the quantification of the major components of the region's carbon balance - fossil fuel CO2 emissions and net fluxes between land ecosystems and the atmosphere. Through spatially-detailed inventories of fossil fuel CO2 emissions and a terrestrial bio...

Climate change and permafrost thaw have been suggested to increase high latitude methane emissions that could potentially represent a strong feedback to the climate system. Using an integrated earth-system model framework, we examine the degradation of near-surface permafrost, temporal dynamics of inundation (lakes and wetlands) induced by hydro-cl...

Adequate quantification of evapotranspiration (ET) is crucial to assess how climate change and land cover change (LCC) interact with the hydrological cycle of terrestrial ecosystems. The Mongolian Plateau plays a unique role in the global climate system due to its ecological vulnerability, high sensitivity to climate change and disturbances, and li...

Both historical and idealized climate model experiments are performed with a variety of Earth system models of intermediate complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and continue through to 2005. The standard simulations inc...

This paper summarizes the results of an intercomparison project with Earth System Models of Intermediate Complexity (EMICs) undertaken in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). The focus is on long-term climate projections designed to: (i) quantify the climate change commitment of different ra...

A global biofuels program will potentially lead to intense pressures on land supply and cause widespread transformations in land use. These transformations can alter the Earth climate system by increasing greenhouse gas (GHG) emissions from land use changes and by changing the reflective and energy exchange characteristics of land ecosystems. Using...

In this study, we investigate possible climate change over Northern Eurasia and its impact on hydrological and carbon cycles. Northern Eurasia is a major player in the global carbon budget because of boreal forests and wetlands. Permafrost degradation associated with climate change could result in wetlands releasing large amounts of carbon dioxide...

Adequate quantification of evapotranspiration (ET) is crucial to assess how climate change and land cover change (LCC) interact with the hydrological cycle of terrestrial ecosystems. The Mongolian Plateau plays a unique role in the global climate system due to its ecological vulnerability, high sensitivity to climate change and distur-bances, and l...

This study investigates the complex terrestrial ecosystems response to extreme weather events using three different land surface models. Previous studies have showed that extreme weather events can have serious and damaging impacts on human and natural systems and they are most evident on regional and local scales. Under climate change, extreme wea...

Both historical and idealized climate model experiments are performed with a variety of Earth System Models of Intermediate Complexity (EMICs) as part of a community contribution to the Intergovernmental Panel on Climate Change Fifth Assessment Report. Historical simulations start at 850 CE and continue through to 2005. The standard simulations inc...

Permafrost degradation is likely enhanced by climate warming. Subsequent landscape subsidence and hydrologic changes support expansion of lakes and wetlands. Their anaerobic environments can act as strong emission sources of methane and thus represent a positive feedback to climate warming. Using an integrated earth-system model framework, which co...

The production of cellulosic biofuels may have a large influence on future land emissions of greenhouse gases. These effects will vary across space and time depending on land-use policies, trade, and variations in environmental conditions. We link an economic model with a terrestrial biogeochemistry model to explore how projections of cellulosic bi...

Land can be used in several ways to mitigate climate change, but especially under changing environmental conditions there may be implications for food prices. Using an integrated global system model, we explore the roles that these land-use options can play in a global mitigation strategy to stabilize Earth's average temperature within 2 °C of the...

The MIT IGSM is used for a study of the climate response to various historical and projected forcings over the period 850-4000 AD. The MIT IGSM includes a zonally-averaged atmospheric model coupled to land and ocean models. Both land and ocean models simulate carbon cycle. Two configurations of the IGSM were used in the simulations; one with the MI...

In recent decades, the largest increase of surface air temperature and related climate extremes have occurred in northern Eurasia. This temperature increase and extreme climate change are projected to continue during the 21st century according to climate models. The changing climate is likely to affect land cover and the biogeochemical cycles in th...

We assessed the uncertainty of the simulated vegetation coverage by the Lund-Potsdam-Jena dynamic global vegetation model (LPJ-DGVM) to changes of parameters and different climate inputs. The analysis was based on a set of 10,000 Monte Carlo ensemble simulations for northern high latitudes (45oN north). The LPJ-DGVM was run under contemporary and f...

During the past decades, nitrogen deposition in China has been substantially increased, with mean values higher than those in the United States and Europe. The elevated nitrogen input, as important part of global changes, has greatly altered ecosystem structure and functioning, and thus exerted significant impacts on carbon cycling. In this study,...

The effects of future climate change and increases in atmospheric CO2 levels in Pennsylvania must be considered in the context of land use and management decisions. While Pennsylvania was originally completely forested at the outset of the colonial period, 19th century land clearing and subsequent regrowth has changed the forest cover of Pennsylvan...

In recent decades, the largest increase of surface air temperature and related climate extremes have occurred in northern Eurasia. This temperature increase and extreme climate are projected to continue during the 21st century according to climate models. The changing climate could affect landcover and the biogeochemical cycles in the region. These...

With the risks of climate change becoming increasingly evident, there is growing discussion regarding international treaties and national regulations to lower greenhouse gas (GHG) emissions. Enforcement of such agreements is likely to depend formally upon national and sectoral emission reporting procedures (sometimes referred to as “bottom-up” meth...

We used a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to examine the methane (CH4) exchanges between terrestrial ecosystems and the atmosphere in Northern Eurasia from 1971 to 2100. Multiple model simulations using various wetland extent datasets and climate change scenarios were conducted to assess the uncertainty of CH4 fluxes,...

Studies indicate that, historically, terrestrial ecosystems of the northern high-latitude region may have been responsible for up to 60% of the global net land-based sink for atmospheric CO 2. However, these regions have recently experienced remarkable modification of the major driving forces of the carbon cycle, including surface air temperature w...

As greenhouse gases, including CO2, accumulate in the atmosphere, the western United States is predicted to undergo large-scale climate warming and reduced summer precipitation in the coming decades. In this study we explore the role of these climate changes with elevated CO2 to determine the plant physiological response on primary productivity and...

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/). Although policymaking in response to the climate change is essentially a challenge of risk management, most studies of the relation of emissions targets to desired climate outcomes are either determi...

Tropical ecosystems play a large and complex role in the global carbon cycle. Clearing of natural ecosystems for agriculture leads to large pulses of CO2 to the atmosphere from terrestrial biomass. Concurrently, the remaining intact ecosystems, especially tropical forests, may be sequestering a large amount of carbon from the atmosphere in response...

1] The magnitude, spatial, and temporal patterns of the terrestrial carbon sink and the underlying mechanisms remain uncertain and need to be investigated. China is important in determining the global carbon balance in terms of both carbon emission and carbon uptake. Of particular importance to climate‐change policy and carbon management is the abi...

Data on expenditures on hunting, fishing, wildlife viewing, and maintenance of public parks and recreational areas for the US are available from the US Census Bureau. For example, banking and borrowing of emissions allowances, in principle requiring dynamic optimization, can be simulated by imposing the theoretical result that their price rises at...

The watersheds of the rivers draining into the Arctic Ocean have experienced a number of changes in climate, land use and other disturbances over the 20th century. We use the Terrestrial Ecosystem Model to examine how simultaneous changes in multiple environmental factors over this time period have influenced the movement of dissolved organic carbo...

In recent decades, the largest increase of surface air temperature and related climate extremes have occurred in northern Eurasia. This temperature increase and extreme climate are projected to continue during the 21st century according to climate models. The changing climate will affect land cover and the biogeochemical cycles in the region. These...

The Western U.S. is predicted to undergo large-scale climate warming and reduced summer precipitation in the coming decades. Combined with increased evapotranspiration, the reduced precipitation and earlier snowmelt could result in enhanced summer drying and increased drought potential. In this study we explore the role of these climate changes wit...

The Brazilian Amazon is one of the most rapidly developing agricultural areas in the world and represents a potentially large future source of greenhouse gases from land clearing and subsequent agricultural management. In an integrated approach, we estimate the greenhouse gas dynamics of natural ecosystems and agricultural ecosystems after clearing...

TheBrazilian Amazon is one of themost rapidly developing agricultural areas in the world and represents a potentially large future source of greenhouse gases from land clearing and subsequent agricultural management. In an integrated approach, we estimate the greenhouse gas dynamics of natural ecosystems and agricultural ecosystems after clearing i...

This study used several model-based tools to analyze the dynamics of the Arctic Basin between 1997 and 2006 as a linked system of land-ocean-atmosphere C exchange. The analysis estimates that terrestrial areas of the Arctic Basin lost 62.9 Tg C yr-1 and that the Arctic Ocean gained 94.1 Tg C yr-1. Arctic lands and oceans were a net CO2 sink of 108....

Recent changes in climate, disturbance regimes and land use and management systems in Northern Eurasia have the potential to disrupt the terres-trial sink of atmospheric CO 2 in a way that accelerates global climate change. To determine the recent trends in the carbon balance of the arctic and boreal ecosystems of this region, we performed a retros...

Background/Question/Methods The magnitude, spatial and temporal patterns of terrestrial carbon sink and the underlying mechanisms remain uncertain and need to be investigated. China is important in determining the global carbon balance in terms of both carbon emission and carbon uptake. Of particular importance to climate-change policy and carbon...

Corrigendum: Sokolov, A., and Coauthors, 2009: Probabilistic forecast for twenty-first-century climate based on uncertainties in emissions (without policy) and climate parameters. J. Climate, 22, 5175–5204. Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for perso...

Tropical ecosystems play a large and complex role in the global carbon cycle. Clearing of natural ecosystems for agriculture leads to large pulses of CO(2) to the atmosphere from terrestrial biomass. Concurrently, the remaining intact ecosystems, especially tropical forests, may be sequestering a large amount of carbon from the atmosphere in respon...

Some recent inverse modeling studies show a carbon sink due to carbon fertilization stimulating uptake by tropical forests. Others find carbon emissions from land-use change make the tropics a net source for carbon. Here, we use a 105-year integrated land-cover and land-use reconstruction with a process-based ecosystem model (the Terrestrial Ecosys...

Studies suggest that high-latitude terrestrial ecosystems have had a significant influence on the global carbon budget by acting as a substantial sink of atmospheric CO2 over the latter part of the 20th Century. However, recent changes in the controlling factors of this sink, including surface air temperature warming and increases in the frequency...

During the last half-century, large areas of the Western U.S., especially the intermountain interior, have experienced increasing drought. IPCC AR4 projections for a range of scenarios consistently show less runoff and soil moisture in the Southwestern U.S. and central Plains indicating that these drought trends will continue into the future. More...

The production of biofuels may lead to enhanced greenhouse gas (GHG) emissions from land to the atmosphere either by directly converting land to biofuel crops, or indirectly, by causing the displacement of food production and other land uses which then require additional land conversions. The importance of indirect GHG emissions from biofuel-relate...

Northern high latitudes are a key part of the global climate system because the net positive energy input to the tropics must ultimately be resolved through substantial energy losses in high latitude regions. Terrestrial ecosystems of northern high latitude regions influence the global climate system through both positive and negative feedbacks inv...