Life is an essential part of how the Earth functions as a planet. While we experience and, for the most part, study ecosystems at human scales, the biosphere also functions as an ecosystem with feedbacks and interactions that are global. How can we extend our knowledge from organisms to understand the global biosphere? I focus on three questions where the global perspective from space-based observations has or will play a crucial role:
- Have we reached a tropical tipping point where emissions dominate over CO2 fertilization?
- How do species, structural and physiological diversity affect the resiliency of ecosystems to climate?
- How do socio-ecological and climatic factors influence cities as ecosystems?
Results/Conclusions
Have we reached a tropical tipping point where emissions dominate over CO2 fertilization?
The tropics, which analyses of CO2 and biomass change show to have been a sink for CO2 have been a persistent source since the El Nino droughts of 2015-2016. These emissions are from repeated droughts and human behavioral change. Is this a decadal variation with uptake to resume or an Earth System tipping point? The view from space sheds light on one of the first and long-predicted abrupt ecosystem responses to climate change.
How do dimensions of diversity affect the resiliency of ecosystems to climate?
Ecologists have long studied how ecosystem structure and composition affect the response to biotic and climate changes. Beginning with Solar-Induced Fluorescence, and continuing with evapotranspiration, we can now measure physiology from space. Active remote sensing quantifiesa ecosystem structure and structural diversity while imaging spectrometers are beginning global measurements of physiological and species diversity. How can we best build a global survey of diversity and ecosystem function?
How do socio-ecological and climatic factors influence cities as ecosystems?
Urban environments function as ecosystems with strong feedbacks from both the altered biophysical environment and the biota to the resultant system. Remote sensing provides a unique vantage, characterizing the biota wall-to-wall, key biophysical processes such as photosynthesis, the heat island and indicators of urban metabolism, emissions of CO2, CH4 and NO2 as well as the urban matrix, structures and impervious surfaces. Preliminary results show, for example, that high rates of photosynthesis in some cities remove substantial amounts of emitted CO2 affecting “urban domes” of carbon dioxide. These data give new perspectives on urban environments and human health in cities.