Jacobson pursued "better understanding air pollution and global warming problems and developing large-scale clean, renewable energy solutions to them".
[2] He has developed computer models[3] to study the effects of fossil fuels, biofuels, and biomass burning on air pollution, weather, and climate.
[6] He discussed and promoted[7][8][9] the conversion of worldwide energy infrastructure to "100% wind, water, and sunlight (WWS) for all purposes"[10] in many interviews[11] Jacobson's 2015 study on transitioning the 50 states to WWS was cited as the scientific basis in House Resolution 540 (2015)[12] and in the 2015 New York Senate Bill S5527 on renewable energy[13] The Green New Deal appears compatible with Jacobson's scholarship.
[29] Jacobson has published research on the role of black carbon and other aerosol chemical components on global and regional climates.
The Solutions Project was started to combine science, business, and culture in an effort to educate the public and policymakers about the ability U.S. states and communities to switch to a "100% renewable world".
"[32] Several of the individual computer code solvers Jacobson developed for GATOR-GCMOM include the gas and aqueous chemistry ordinary differential equations solvers SMVGEAR[33] and SMVGEAR II,[34][35] alongside a slew of other related and different modules,[36][37][38][39][40][41][42][43][excessive citations] The GATOR-GCMOM model has incorporated these processes and has evolved over several decades.
[44][45][46][47][48][49][50][51][excessive citations] One of the most important fields of research that Jacobson has added to, with the aid of GATOR-GCMOM, is re-defining the range of values on exactly how much diffuse tropospheric black carbon from fossil fuel, biofuel, and biomass burning affects the climate.
On the other hand, greenhouse gases warm the atmosphere by trapping thermal-infrared heat radiation that is emitted by the surface of the Earth.
[53] Two additional important effects of soot that contribute to its strong global warming that Jacobson has analyzed include its impact on melting snow and sea ice[54][54] and on evaporating clouds.
Jacobson has updated and expanded this 2009 paper as the years progress, including a two-part article in the journal Energy Policy in 2010.
[59][60][61] In 2015, Jacobson was the lead author of two peer reviewed papers, one of which examined the feasibility of transitioning each of the 50 United States to a 100% energy system, powered exclusively by wind, water and sunlight (WWS), and the other that provided one proposed method to solve the grid reliability problem with high shares of intermittent sources.
[62] In 2016 the editorial board of PNAS selected the grid integration study of Jacobson and his co-workers as best paper in the category "Applied Biological, Agricultural, and Environmental Sciences" and awarded him a Cozzarelli Prize.
[63] Jacobson has also published papers to transition 139,[64] 143,[65] 145[66][67] and 149[68] countries as well as cities and 74 metropolitan areas[69] to 100% WWS renewable energy for all purposes.
Publications from 2011 to 2015, that analyzed, with different methodologies, various strategies to get to a global zero or low carbon economy, by circa 2050, reported that a renewables-alone approach, would be "orders of magnitude" more expensive and more difficult to achieve than other energy paths that have been assessed.
Jacobson arrived at this conclusion of "25 times more carbon emissions than wind, per unit of energy generated" (68–180.1 g/kWh), by specifically expanding on some concepts that are highly contested.
An assumption that Jacobson's debating opponent similarly raised, during the Ted talk Does the world need nuclear energy?
[89] The Intergovernmental Panel on Climate Change(IPCC) regard Yale University's Warner and Heath's methodology, used to determine the Life-cycle greenhouse-gas emissions of energy sources, as the most credible, reporting that the conceivable range of total-life-cycle nuclear power emission figures, are between 4-110 g/kWh, with the specific median value of 12 g/kWh, being deemed the strongest supported and 11 g/kWh for Wind.
Aside from the time required for planning, financing, permitting, and constructing a power plant, for every energy source that can be analyzed, the time required and therefore Jacobson's "opportunity costs" also depends on political factors, for example hypothetical legal cases that can stall construction and other issues that can arise from site specific NIMBYISM.
[91][92] Health physicist Kathryn Higley of Oregon State University wrote in 2012, "The methods of the study were solid, and the estimates were reasonable, although there is still uncertainty around them.
[17] Jacobson and his coauthors published a response to the critical paper[18] and also requested the journal and authors to either correct "false factual claims" of modeling error or retract the article.
After both declined, Jacobson filed a lawsuit in 2017 against the Proceedings of the National Academy of Sciences and Christopher Clack as the principal author of the paper for defamation.
"[22][23][94] In 2022, Jacobson appealed a trial court order for him to pay $428K in legal fees incurred by defendants in his lawsuit prior to his voluntary dismissal of it.
[29] Jacobson was an expert witness in Navahine v. State of Hawaii, the world’s first constitutional climate case to reach a settlement.