BIOGEOSPHERIC CHANGE RESPONSE OF ECOSYSTEM STRUCTURE AND DISTRIBUTION TO ALTERED FORCING © 2007 T. Kittel Clarice Bassi - Anavilhanas

DRIVERS OF FUTURE ECOLOGICAL CHANGE: MULTIPLE FACTORS  Climate Change – Anthropogenic forcings: Greenhouse gas emissions (GHG): CO 2, CH 4, N 2 0, etc Sulfate aerosols (SUL), Cloud condensation nuclei (dust,..) Landuse change  Surface biophysical properties Stratospheric Ozone  Disturbance – Landuse change: Deforestation, cropland conversion Overgrazing, desertification Invasive species  Direct Chemical Effects: CO 2 N deposition / acid deposition Toxic pollution: Tropospheric ozone, Salt accumulation, …

The Source – Anthropogenic Forcing Greenhouse Gas Emissions Dioxide Increasing CO 2 – Fossil fuels Land conversion Biomass burning Effects = Radiatively-active  Climate effect Biologically-active: Increased water and nutrient use efficiency  Fertilization

Roads & fires - Amazon Landcover Change The Source – Anthropogenic Forcing  Changes in energetics & hydrology of the terrestrial surface  Changes in ecosystem biogeochemistry & emissions  Regional to global climate

Aircraft tracks, Bay of Biscay, E Atlantic Aerosols – sulfate, dust, soot, sea salt, … The Source – Anthropogenic Forcing  Haze / Cloud Condensation Nuclei  Changes in radiative properties of the atmosphere Dust from Gobi Desert embedded in a storm approaching California

Manifestation of Change – Climate Hemispheric Animation Surface Air Temperatures “We are entering a period of consequences” - Winston Churchill

Manifestation of Change – Climate Precipitation

Manifestation of Change - Biosphere Estimated changes in net primary productivity Increased North American NPP

The Future – Climate Projected Change – Annual Surface Air Temperature 2020’s 2090’s Change (°C) relative to Greatest response in the Northern High Latitudes

The Future – Climate Projected Change – Precipitation: Northern Winter % Change relative to ’s

GLOBAL VEGETATION MODELS & the role of soil (Kittel et al. 2000) Structure of MC1

VEMAP2 REGIONAL VEGETATION RESPONSE Animation: see notes pane for instructions

SCIENTIFIC UNCERTAINTIES: CLIMATE SENSITIVITY Emission scenarios  Business-as-usual  Carbon Stabilization Climate model differences = the shaded envelop Models similar conceptually Different responses driven by –  Different model representations  Uncertainties in scaling up microphysical processes – ppt, radiation & clouds ‘The devil is in the details’ Business as Usual CO2 Stabilization (

CGCM1 HADCM2SUL MC1LPJ Model Uncertainty – Total Ecosystem Carbon Uncertainty – Sources “Same Ecology, Different Results” - at the regional level

Total Ecosystem Carbon Uncertainty – Sources “Same Ecology, Different Results” - with time

(1) Very character of regional climates will likely change over the next decades: Multivariate  Higher surface temperatures – different responses for T min T max  Regionally varying changes in precipitation, cloud cover (light regime), wind regimes, etc. In means, but in also seasonality and interannual variability Trends likely not to be monotonic  As circulation patterns shift, & the system passes thresholds Giving rise to novel climates The Certainties – Climate “What do we know for sure?”

(2) Probable climate changes are of a magnitude and character to be significant for populations, communities, and landscapes: Geographic ranges Phenologies/life cycles Species interactions out of phase:  Foodwebs, competition, pollination Ecosystem structure & function  Resilience of many ecosystems is likely to be exceeded Giving rise to novel ecosystem types Certainties – The Biosphere

(3) The magnitude of uncertainties ≥ magnitude of system sensitivity The magnitude of what’s certain will change everything Certainties – The Biosphere

ACTION UNDER SUFFICIENT BUT LIMITED KNOWLEDGE? “Least regrets” policy approach – Develop policy that doesn’t rely on any single scenario of future change, but which reduces overall system vulnerability Maintain or restore integrity of natural systems  Large preserves, landscape corridors, Clean Water Act …  A focus on ecosystem services Develop infrastructure enhancing resiliency of socio-economic systems – to changes in climatic forcing regardless of direction  Landuse policy in areas currently prone to fire, flooding, hurricanes … Individual Action – Carbon & ecological sustainability Community involvement