Earth Systems

Carbon dioxide (CO2) and methane (CH4) are the main greenhouse gases, contributing about 81% of the total human induced radiative forcing. Sufficient observations exist to quantify the global budget of carbon dioxide and methane which is necessary for calculating the resulting radiative forcing. Still, more observations are needed to constrain their time evolution and regional budgets which are needed for climate change mitigation policies. Atmospheric observations are particularly scarce on the African continent, despite Africa’s significant CO2 emissions from agriculture, biomass burning and land use changes, as well as methane emissions from wetlands. there are very few low frequency flask measurements due to limited logistics and there is no land based station at all in equatorial Africa. Satellite observations can only provide an incomplete record due to frequent clouds and aerosol in the equatorial belt.

We have set up a high-frequency in-situ greenhouse gases monitoring station in North West Rwanda at Mount Mugogo. The station is intended to be a long-term station, hence, filling the gap of current lack of measurements in Equatorial Africa. The station is part of the Advanced Global Atmospheric Gases Experiment (AGAGE) and follow its calibration protocols and operational standards, therefore, providing data of internationally recognized quality standards. We have found that massive regional scale biomass burning largely drives the bi-model seasonal cycle of carbon dioxide, carbon monoxide and black carbon with the burning following the shift of the inter-tropical convergence zone. The seasonal cycle of methane is largely driven by the inter-hemispheric gradient, where methane-rich northern hemisphere air masses are advected to the station during the northern winter.

We have used the Reversible Jump Markov Chain Monte Carlo methods to estimated optimized methane and carbon dioxide emissions in the Central and East African region. We have found that the region emitted about 25 Tg of CH4 and 139 Tg of CO2 in 2016.

Amid much uncertainty about the future of the global climate and efforts aimed at preventing its most damaging impacts, graduate students affiliated with the MIT Joint Program on the Science and Policy of Global Change are hard at work exploring some of the challenges and possible solutions that lie ahead. They are also sharing their knowledge with the MIT community.

Short-term variability and long-term change in climate pose a challenge to water planners. Some climate uncertainties can be reduced over time as new information is collected, while others are irreducible. This presentation shows how flexible water-supply infrastructure planning can help mitigate climate risk at lower cost, especially for uncertainties with high learning potential

The weather in a few days can be difficult to predict, especially with certain phenomena such as thunderstorms. If this is the case, then how can we trust climate projections over several decades? This session’s co-leaders discuss the similarities and differences between predicting next week's weather and the climate in 2100, and how they allow us to make confident climate projections.

Embedded within the climate system are many nonlinear feedback systems and possible tipping points , making prediction of future climate difficult. Co-leaders of this session discuss such mechanisms of the climate system; Earth-system models; the role of clouds, oceans, land cover and biology in the climate system; and how extreme weather relates to climate change.

MIT Joint Program-affiliated researcher and Institute for Data, Systems, and Society (IDSS) PhD student Sarah Fletcher has won a 2017 American Geophysical Union (AGU) Outstanding Student Paper Award for her paper, “Urban water supply infrastructure planning under predictive groundwater uncertainty: Bayesian updating and flexible design.” Granted to the top five percent of student participants, the award inc

Pages

Subscribe to Earth Systems