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Climate Central developed an Urban Heat Intensity Index for 159 U.S. cities, finding that New Orleans, Newark, New York City, Houston, and San Francisco have the highest intensity scores. The report identifies albedo, lack of greenery, population density, and building height as primary drivers of the UHI effect. These conditions exacerbate heat waves, worsen air quality through ground-level ozone formation, and disproportionately affect vulnerable populations, particularly those in formerly redlined neighborhoods. Proposed solutions include short-term emergency cooling measures and long-term infrastructure changes such as planting trees, installing green and cool roofs, and deploying solar energy.

A letter from a Stockholm Environment Institute scientist to the Massachusetts Attorney General arguing that Harvard's fossil fuel investments are misaligned with the Paris Agreement and contribute to global health and environmental crises.

The document critiques Governor Charlie Baker's veto of bill S.2995, which proposed a voluntary net-zero stretch code for new construction in Massachusetts. It argues that electrification is the most cost-effective path to meeting the state's 2050 net-zero carbon emissions target, citing state analysis and RMI research showing that all-electric single-family homes in Boston are already cheaper to build and operate than gas-powered ones. The text highlights that net-zero affordable housing is already viable in the state and warns that continuing to invest in Massachusetts' aging gas pipeline infrastructure—estimated to require $15.5 to $16.6 billion in repairs—is a poor financial decision for ratepayers.

The document reports that Massachusetts has the 3rd most vulnerable affordable housing stock in the United States regarding future coastal flooding. By 2050, 4,818 units (2% of the state's stock) could be exposed to coastal flooding. Boston is identified as particularly at risk, with expected annual exposure increasing from 609 units currently to 3,042 units by 2050, a 400% increase. Other high-risk cities in the state include Quincy, Cambridge, and Revere, all of which rank among the top 20 cities nationwide for affordable housing units at risk.

The document highlights that Massachusetts has the third most vulnerable affordable housing supply in the United States regarding future coastal flooding. By 2050, 4,818 affordable housing units in the state (2% of its supply) could be exposed to coastal flooding. Boston is identified as the most affected city, with an expected 400% increase in exposed units by 2050, reaching 3,042 units. The report notes that affordable housing is particularly vulnerable because it is often older, of lower quality, and lacks resilience features like flood protection.

The report analyzes the climate impact of transportation network companies (TNCs) in seven major U.S. cities. It finds that non-pooled ride-hailing trips emit 47% more than private vehicle trips of the same length, largely due to 'deadheading' (driving without passengers). When accounting for the modes of transport that ride-hailing displaces—including mass transit, walking, and biking—typical ride-hailing trips are approximately 69% more polluting than the trips they replace. The analysis suggests that a transition to electric vehicles and an increase in pooling rates to 50% could reduce these emissions by 52% relative to displaced trips.

The report finds that Rhode Island can feasibly reduce its greenhouse gas emissions by 70-80% by 2030, 2040, or 2050 by focusing on electrifying transportation and heating, improving energy efficiency, and transitioning the electricity grid to renewables. A critical finding is that updated science on methane leakage from natural gas infrastructure reveals that 2017 emissions were approximately 45% higher than previously estimated in 2016. While the 2050 pathway is relatively low-cost, the 2030 pathway requires a significant spending spike, resembling a 'Green New Deal' approach. The study emphasizes that reaching net-zero requires the complete phase-out of natural gas and further research into industrial decarbonization and carbon sequestration.

A Climate Central analysis of 239 U.S. cities reveals that 83% have seen an increase in annual average days with a heat index of 90°F or higher since 1979. The report highlights the danger of exertional heat illness (EHI), noting that heat-related illnesses are a leading cause of death or disability among high school athletes. It details regional trends, such as substantial increases in the Pacific Northwest and extended heat seasons in the South, while noting that climate change is intensifying these trends. The document provides safety recommendations for coaches and athletes, including the use of wet bulb globe temperature (WBGT) monitoring and gradual heat acclimatization.

The Union of Concerned Scientists analysis reveals that Asian American, African American, and Latino residents in Massachusetts face significantly higher exposure to PM2.5 from cars, trucks, and buses than white residents. This disparity is attributed to historical decisions regarding transportation, housing, and land use. The document advocates for prioritizing clean transportation technologies—such as electric vehicles and buses—and infrastructure improvements in the most burdened communities to reduce health inequities.

Climate Central's analysis of U.S. weather data from 1970 to 2018 reveals a broad warming trend, with 91% of assessed stations seeing winter temperatures rise by at least 1°F. This warming threatens the winter sports economy, which supported over 191,000 jobs and contributed $11.3 billion to the national economy in the 2015-16 season. The report highlights a decline in below-freezing days and divergent snowfall trends, with significant decreases in the Western U.S. and increases in the Great Lakes region. Future projections suggest that unchecked emissions could rob states like Colorado of more than a month of below-freezing days by midcentury.

The report argues that targeting rental properties for energy efficiency is a high-impact strategy for cities to meet climate goals, as rentals often suffer from a 'split incentive' where owners do not pay utility bills. Using Boulder's 'SmartRegs' program as a model, the document outlines a seven-step roadmap for other cities: determining fit, analyzing impact, consulting stakeholders, developing financing, implementing measurement tools, establishing compliance, and creating disclosure frameworks. RMI's analysis of five US cities suggests that MESR policies could significantly reduce carbon emissions at a relatively low cost to municipal governments.

The Union of Concerned Scientists reports that the EPA's January 25, 2018, withdrawal of the "once in, always in" (OIAI) policy allows industrial facilities to be reclassified from "major sources" to "area sources" of hazardous air pollutants (HAPs). This reclassification removes the requirement for facilities to use Maximum Achievable Control Technology (MACT), which the authors estimate was used by 70 percent of major sources in 2014 to keep emissions at or below thresholds of 10 or 25 tons per year. The document warns that area sources are not regulated or inspected as stringently, potentially increasing emissions of toxic substances like chlorine, benzene, and styrene. The analysis identifies at least 21 states at risk of increased pollution, with specific high-risk clusters in Louisiana's "Cancer Alley," Houston, Chicago, and the New York-Newark urban area.

The guide explains that the carbon-reduction impact of renewable energy projects varies by location because different projects displace different types of power plants. It argues that relying on proximity to operations as a proxy for quality may limit environmental benefits, suggesting instead that buyers target the most carbon-intensive areas to maximize avoided emissions.

The report argues that California's public infrastructure is deteriorating and based on outdated historical climate data, making it vulnerable to a 'new normal' of extreme heat, sea level rise, wildfires, and erratic precipitation. It proposes a 'climate-smart' framework based on rigorous science, equitable outcomes, financial transparency, and holistic planning. Key barriers identified include outdated design codes, a lack of actionable climate data for engineers, and systemic underinvestment in underserved communities. The author recommends updating state standards, establishing a centralized coordinating center for climate information, and adopting innovative financing mechanisms like resilience bonds to protect critical services and vulnerable populations.

The document argues that federal light-duty vehicle standards set by the EPA and NHTSA in 2012 provide significant benefits to Massachusetts, including fuel savings, job creation, and emissions reductions. By 2030, the average Massachusetts household is projected to be $2,650 richer due to gas savings outweighing the upfront cost of more efficient vehicles. To date, the state has saved $700 million, and the standards are expected to create 15,200 new jobs in the state. Environmentally, the standards eliminate global warming emissions equivalent to those produced by providing electricity to the city of Boston.

The Union of Concerned Scientists (UCS) identifies Massachusetts communities at risk of 'chronic inundation'—defined as high tide flooding 10% or more of usable, non-wetland area at least 26 times per year. Under an intermediate sea level rise scenario, five communities will face this by 2060 and 13 by 2100. Under a high scenario, those five communities will be affected by 2045, with 23 communities affected by 2100. The report highlights that working-class towns like Chelsea and Revere are particularly vulnerable, with up to 30% of Chelsea's land area potentially chronically inundated by 2060. The UCS argues that limiting warming to approximately 1.8°C could spare several communities, including Boston and Cambridge, from this fate. Recommended responses include phasing out risky coastal development, enhancing FEMA's mitigation programs, and creating new policies for managed retreat and relocation.

The 2016 assessment reveals a significant decline in elephant ivory availability in historical physical markets like New York City, San Francisco, and Los Angeles, potentially due to state-level bans. However, the market appears to be pivoting toward online platforms and states without strict regulations, such as Washington, DC and Oregon. The report documents 1,589 items in physical retail and 2,056 items across six online platforms, noting widespread confusion among vendors regarding legal exemptions and a trend of mislabeling ivory as 'bone' or 'mammoth' to evade detection.

The document advocates for increasing electric vehicle (EV) availability in the Northeast and Mid-Atlantic, noting that while 55% of regional consumers are interested, availability lags significantly behind California. It calls for the expiration of a regulatory exemption that allows sales in California to count toward compliance in Northeast states and suggests updating ZEV program credits to account for rapid improvements in battery range.

The Union of Concerned Scientists analysis finds a significant disparity in how automakers deploy electric vehicles (EVs) across the United States. While BMW, General Motors, Nissan, and Tesla are identified as leaders, others like Honda, Toyota, and Fiat Chrysler are labeled laggards due to limited model availability or a lack of plug-in offerings. The report highlights a stark geographic divide, noting that California's Zero Emission Vehicle policy has made it the only state where all available US EV models are offered, while consumers in other regions face severe shortages of EVs at dealerships.

The report analyzes the US electric vehicle (EV) market as of 2016, finding that while cumulative sales were nearing 500,000, progress among automakers is uneven. BMW, General Motors, Nissan, and Tesla are identified as leaders, while Honda, Toyota, and Fiat Chrysler are characterized as laggards. A significant disparity in vehicle availability exists between California and the rest of the US, largely attributed to California's Zero Emission Vehicle (ZEV) program. The authors argue that limited model availability and poor dealership inventory outside California hinder the national transition to electric transportation.