The Biosphere: Climatic Cause and Effect

The Biosphere: Climatic Cause and Effect Climate and Global Change Geoscience Workshop 2002 The Biosphere: Climatic Cause and Effect Dr. Peter HarleyBiosphere-Atmosphere Interactions GroupAtmospheric Chemistry DivisionNational Center for Atmospheric Research The Biosphere: Climatic Cause and Effect

The Biosphere: Climatic Cause and Effect Acknowledgements—Thanks for providing slides! Gordon Bonan, CGD, NCAR Alex Guenther, ACD, NCAR Joanie Kleypas, CGD, NCAR Russ Monson, EPOB, CU David Schimel, CGD, NCAR Christine Wiedinmyer, ACD, NCAR The Biosphere: Climatic Cause and Effect

IPCC: Impacts of Climate Change The Biosphere: Climatic Cause and Effect

The Biosphere: Climatic Cause and Effect ClimateBiosphere Effects of Increasing CO2 on Biosphere (partial list) Changes in plant physiology Changes in higher trophic levels Damage to coral reef ecosystems Effects of Environmental Warming (partial list) Changes in phenology (timing of growth/reproduction) Changes in geographic range of organisms Changes in community structure Damage to coral reef ecosystems The Biosphere: Climatic Cause and Effect

GAIA: A New Look at Life on Earth “. . . the physical and chemical condition of the surface of the Earth, of the atmosphere, and of the oceans has been and is actively made fit and comfortable by the presence of life itself. This is in contrast to the conventional wisdom which held that life adapted to the planetary conditions as it and they evolved their separate ways.” James Lovelock, 1979 The Biosphere: Climatic Cause and Effect

GAIA – forming and regulating atmosphere? “An awesome thought came to me. The Earth’s atmosphere was an extraordinary and unstable mixture of gases, yet I knew that it was constant in composition over quite long periods of time. Could it be that life on Earth not only made the atmosphere, but also regulated it – keeping it at a constant composition, and at a level favorable for organisms?” James Lovelock, 1991 The Biosphere: Climatic Cause and Effect

Earth’s Improbable Atmosphere Oxidizing Reducing Inert “If life on Earth ceased, all the elements in the crust, oceans and atmosphere would react together until a state close to chemical equilibrium was reached. The planet would become a hot, waterless, and inhospitable place.” (290oC) James Lovelock, 1979 Mars Venus Dead Earth Earth O2 CO2 CH4 H2 N2 Ar The Biosphere: Climatic Cause and Effect

Atmospheric Composition (simplified) • Major gases • 21% Oxygen (O2) and 79% Nitrogen • Trace gases • Stable • Carbon dioxide, nitrous oxide, methane, hydrogen • Global radiation balance, oxidant sinks • Reactive • Isoprene, dimethyl sulfide, oxides of nitrogen, ozone • Photochemical oxidant production, oxidant sinks, secondary particle formation, global radiation balance, air pollution The Biosphere: Climatic Cause and Effect

Lovelock’s GAIA Contribution Whether or not you accept the extreme versions of the GAIA hypothesis, the publication of “GAIA, A New Look at Life on Earth” (1979) has influenced the way in which scientists and the general public view the Earth. It is still being hotly debated 25 years later. Raised consciousness! Holistic view of the Earth. Earth from space. Focused attention on the role of the Biosphere in Atmospheric processes Promoted interdisciplinary research (now strongly supported by NCAR) Stimulated research to prove/disprove GAIAN regulatory mechanisms Fostered a systems approach to Earth Science in which the Earth is viewed as a complex system, with biogeochemical cycling between Geosphere, Hydrosphere, Biosphere and Atmosphere with important interactions and feedbacks between them The Biosphere: Climatic Cause and Effect

Denver Post July 2, 2002 What if a crystal ball could tell whether the West is likely to suffer through sweaty stretches of 90-degree days every summer? What if that same future forecaster could divine whether water restrictions will be a constant for future American farmers? Scientists perched atop a Boulder bluff are helping to pose those "what if" climate questions right now. Teaming forces with climate gurus across the nation, they have created a computer model that lets them divvy up the Earth's complex climate drivers - atmosphere, ocean, land and sea ice - among dozens of high-speed computers to ask questions about our future. The National Center for Atmospheric Research in Boulder has created such climate models in the past. In creating the Community Climate System Model, Version 2, NCAR is working with more than 100 climate researchers in a dozen universities and a trio of Department of Energy research labs. The goal: a computer model that captures the Earth's climate system. NCAR teams for climate model Boulder lab allies with scientists nationwide to predict trends By Diedtra HendersonDenver Post Science Writer The Biosphere: Climatic Cause and Effect

Satellite-Derived Plant Geography Newest generation of Land Surface Models classify all vegetation as falling into one of six broad categories. The Biosphere: Climatic Cause and Effect

Community Land Model Hydrology Precipitation Evaporation Interception Canopy Water Momentum Flux Wind Speed 0 ua Transpiration Throughfall Stemflow Sublimation Evaporation Infiltration Surface Runoff Snow Melt Soil Water Redistribution Drainage Snow River Flow Soil Water Surface Runoff Ground Water Lake Ocean Biogeophysics Sensible Heat Flux Latent Heat Flux Photosynthesis Longwave Radiation Diffuse Solar Radiation Direct Solar Radiation Reflected Solar Radiation Emitted Long- wave Radiation Absorbed Solar Radiation Soil Heat Flux Heat Transfer The Biosphere: Climatic Cause and Effect

Community Land Model Dynamic Vegetation Sapwood 0 500 1000 0.01 PPFD (molm-2s-1) 0 15 30 Temperature (C) g CO2g-1s-1 0 -10 25 60 Temperature (C) 0 -1 -2 Foliage Water Potential (MPa) 0 1500 3000 Vapor Pressure Deficit (Pa) 0 500 1000 Ambient CO2 (ppm) 6 6 6 4 4 4 1 2 2 2 0 0 0 Relative Rate 0 0 100 Soil Water (% saturation) 0 1 2 Foliage Nitrogen (%) Foliage Root 0.5 0.3 g CO2g-1s-1 g CO2g-1s-1 0 0 -10 25 60 -10 25 60 Temperature (C) Temperature (C) 8 Relative Rate 1 15 0 30 Temperature (C) Ecosystem Carbon Balance Vegetation Dynamics Photosynthesis Growth Respiration g CO2g-1s-1 Autotrophic Respiration g CO2g-1s-1 Litterfall Heterotrophic Respiration g CO2g-1s-1 Nutrient Uptake The Biosphere: Climatic Cause and Effect

Land Surface Model Vegetation Dynamics The model can predict for each grid cell the change in vegetation over time. This example is for a single grid cell in Canada, following a forest fire in year 0. The Biosphere: Climatic Cause and Effect

The Biosphere: Climatic Cause and Effect ClimateBiosphere Clouds and Precipitation Radiative Effects Absorption at surfaceRadiatively-active gases Effects of Biosphere on Climate (partial list) Vegetation affects albedo CH4 from wetlands, rice paddies, termites, flatulence - Role of terrestrial biosphere in global CO2 budget - Role of marine phytoplankton emissions on aerosols/clouds - Role of VOC emissions in O3 formation Evapotranspiration and rainfall The Biosphere: Climatic Cause and Effect

Global Radiation Balance (Simplified) Transmitted to space (12) Incoming solar radiation (100) Reflected by atmosphere (25) Absorbed by atmosphere and re-radiated back to earth (88) Absorbed by atmosphere (25) Reflected by surface (5) Emitted thermal radiation (100) Absorbed by surface (45) The Biosphere: Climatic Cause and Effect

Radiative Forcing Potentials The Biosphere: Climatic Cause and Effect

The Biosphere: Climatic Cause and Effect ClimateBiosphere Clouds and Precipitation Radiative Effects Absorption at surfaceRadiatively-Active Gases Effects of Biosphere on Climate (partial list) Vegetation affects albedo CH4 from wetlands, rice paddies, termites, flatulence - Role of terrestrial biosphere in global CO2 budget - Role of marine phytoplankton emissions on aerosols/clouds - Role of VOC emissions in O3 formation Evapotranspiration and rainfall The Biosphere: Climatic Cause and Effect

Mauna Loa Observatory CO2 Data In addition to documenting the large increase in atmospheric CO2 over the last several decades, these data clearly identify the signature of the terrestrial biosphere in the annual CO2 fluctuations. The Biosphere: Climatic Cause and Effect

Carbon Cycle The Biosphere: Climatic Cause and Effect

Global Carbon Budget Atmosphere 750 753 Global Net Primary Production and Respiration Fossil Fuel Emissions Land Use Change Ocean Surface Exchange 5.5 1.6 61.5 60 60 0.6 90 92 90 Vegetation 610 Soils 1580 Surface Ocean 1020 Fluxes in Gt C y-1 Pools in Gt C Intermediate and Deep Ocean 38,100 The Biosphere: Climatic Cause and Effect

Carbon Budget – Terrestrial Sink The Biosphere: Climatic Cause and Effect

Mauna Loa CO2 Data – Amplitude Changes Keeling, CD et al., Increased activity of northern vegetation inferred from atmospheric CO2 measurements. Nature 382:146 (1996). The Biosphere: Climatic Cause and Effect

Global CO2 Flux Network Global distribution of Fluxnet sites The Biosphere: Climatic Cause and Effect

Above-Canopy Towers for Measuring Ecosystem CO2 Exchange Towers are instrumented to measure instantaneous fluxes of CO2 to or from the forest ecosystem, using a technique called Eddy Covariance or Eddy Correlation. Summed over time, these measurements can give us daily, weekly or annual Carbon balances, to answer the question: Is the forest a source of CO2 to the atmosphere or a sink which removes CO2 from the atmosphere? What environmental factors control how much Carbon is removed? The Biosphere: Climatic Cause and Effect

What is Eddy Correlation? What is eddy correlation? A measurement technique for surface atmosphereexchange that makes use of turbulence and concentration measurements The Biosphere: Climatic Cause and Effect

3-D Sonic Anemometer Measures wind speed in 3 dimensions very rapidly (9 Hz). CO2 close to the anemometer is measured simultaneously. By noting how the CO2 concentration varies with the vertical wind speed, it is possible to calculate the CO2 flux into or out of the forest (Trust me!) The Biosphere: Climatic Cause and Effect

Eddy Covariance Technique The Biosphere: Climatic Cause and Effect

Two Years of CO2 Exchange Niwot Ridge, CO • Interannual variation in the seasonal pattern of carbon sequestration • Interannual variation in the amount of carbon sequestration The Biosphere: Climatic Cause and Effect

Ancillary Measurements Understanding CO2 Uptake/Release Automated Dendrometer Photosynthesis Soil Carbon & Litter Soil Respiration Bole Respiration The Biosphere: Climatic Cause and Effect

Spring-time Initiation of CO2 Uptake • Control over springtime initiation of NEE by soil temperature • Concomitant initiation of tree bole expansion The Biosphere: Climatic Cause and Effect

Terrestrial Carbon Sink Why and How Long? • Human activities (fossil fuel use and land-use) perturb the carbon cycle -- increasing the atmospheric concentration of carbon dioxide • The current terrestrial carbon sink is caused by land management practices, higher carbon dioxide, nitrogen deposition and possibly recent changes in climate • This uptake by the terrestrial biosphere will not continue indefinitely. The question is when will this slow down, stop or even become a source? • Land management results in the sequestration of carbon in three main pools -- above and below ground biomass and soils The Biosphere: Climatic Cause and Effect

Terrestrial Biosphere predicted to take up C but will level off or reverse next century The Biosphere: Climatic Cause and Effect

Marine Aerosols from Algal Emissions can affect Climate O’Dowd et al., Marine aerosol formation from biogenic iodine emissions, Nature 417, 632 - 636 (2002) The Biosphere: Climatic Cause and Effect

Phytoplankton and DMS “Charlson et al. (1987) described a multi-stage negative feedback phenomenon that links biology with climate change. The process begins with an initial impetus for warming that stimulates primary production in marine phytoplankton. This enhanced process leads to the production of more copious quantities of dimethylsulphonio -propionate, which leads in turn to the evolution of greater amounts of dimethyl sulphide, or DMS, in the surface waters of the world's oceans. Larger quantities of DMS diffuse into the atmosphere, where the gas is oxidized, leading to the creation of greater amounts of acidic aerosols that function as cloud condensation nuclei or CCN. This leads to the creation of more and brighter clouds that reflect more incoming solar radiation back to space, thereby providing a cooling influence that counters the initial impetus for warming.” Negative feedbacks like this is how GAIA is supposed to work. The Biosphere: Climatic Cause and Effect

GAIA Gone Mad: Don’t Worry, Be Happy! “As time marches on, and more and more studies of this nature are conducted, it becomes ever more clear that earth's biosphere has a number of very effective ways of combating extreme temperature changes; and in view of their efficacy, it would seem we have little to worry about in the way of CO2-induced global warming.” The Biosphere: Climatic Cause and Effect

Aerosol Formation from CH2I2 O’Dowd et al., Marine aerosol formation from biogenic iodine emissions, Nature 417, 632 - 636 (2002) The Biosphere: Climatic Cause and Effect

Volatile Organic Compounds emitted from Vegetation R. Fall 1999 The Biosphere: Climatic Cause and Effect

Global Biogenic VOC Emissions Vegetation foliage and other biogenic sources: ~ 1 x 1015 g C y-1 Fossil fuel combustion and other anthropogenic sources: ~ 1 x 1014 g C y-1 The Biosphere: Climatic Cause and Effect

Tropospheric O3 Chemistry (Greatly Simplified!!) In the presence of sunlight and Nitrogen Oxides (NOx), VOC contribute to tropospheric O3 formation. Additionally, because they react readily with OH radical (the major atmospheric scrubber), VOC can also indirectly affect the concentrations of other atmospheric constituents, like CH4. O3 and CH4 are both radiatively active. The Biosphere: Climatic Cause and Effect

Biosphere – VOC Interactions O3 , NOx , CH4 RONO2 , OH, • CO2 ,N2O,NOy Atmospheric Radiative Physical Constituents balance Environment Trace gas Trace gas Emission temp, light deposition Biosphere The Biosphere: Climatic Cause and Effect

BVOC Emission Modeling: Environmental Conditions BVOC Emission Solar radiation Temperature The Biosphere: Climatic Cause and Effect

Modeling Changes in Atmospheric Chemistry Resulting from Land Use Change Goal: Investigate the changes in global chemistry and climate that result from changes in land use and biogenic isoprene emissions • Land use changes occurring globally • Many of the forested areas of the world, particularly in the U.S. and the Amazon, are seeing significant land use changes • Forest replaced by pasture, urban landscapes and agriculture • Changes in land use can affect the biogenic emissions from these areas • Atmospheric chemistry and climate can be altered as a result of the changes in biogenic emissions. The Biosphere: Climatic Cause and Effect

Effect of Forest Removal on Isoprene Emission Effects on July isoprene emissions if forest is replaced by pasture (Brazil) or suburbs (Southeastern U.S.) The Biosphere: Climatic Cause and Effect

Effect of Forest Removal on O3 Levels Effects on July O3 concentrations if forest is replaced by pasture (Brazil) or suburbs (Southeastern U.S.) The Biosphere: Climatic Cause and Effect

IPCC: Impacts of Climate Change The Biosphere: Climatic Cause and Effect

Climate Change is not Uniform over the Earth Although globally averaged temperatures have increased by 0.6 oC over the past century, changes in both temperature and precipitation are very non-uniform. As a result, regional impacts on organisms, ecosystems and the Biosphere in general can be substantial, and are already being documented. Walther et al., Ecological responses to recent climate change, Nature 416:389 (2002) The Biosphere: Climatic Cause and Effect

Threshold Concept Ecological systems have many interacting non-linear processes and are thus subject to abrupt changes and threshold effects arising from relatively small changes in driving variables, such as climate. For example: Temperature increase beyond a threshold, which varies by crop and variety, can affect key development stages of some crops and result in severe losses in crop yields. The Biosphere: Climatic Cause and Effect

The Biosphere: Climatic Cause and Effect