c. 1700 b.c.e.: King Minos of Crete has running water for bathing and sewage disposal in his palace at Knossos.

c. 500 b.c.e.: Athens, Greece, establishes what may have been the first city dump in the Western world, accompanied by a ban against throwing garbage into the streets.

1388: In an early attempt to control municipal pollution, the English Parliament prohibits dumping wastes in the public waterways.

1580: Queen Elizabeth creates a green belt around London by prohibiting construction of new buildings within three miles of the city wall.

1657: The Common Council of New Amsterdam (now New York City) establishes public dumps, prohibits dumping refuse in the street, and requires residents to keep the streets in front of their homes clean.

1833: English chemist and meteorologist Luke Howard describes the “urban heat island” effect in The Climate of London, noting that the city “partakes much of an artificial warmth, induced by its structure, by a crowded population, and the consumption of great quantities of fuel.”

1842: Edwin Chadwick issues a report on the sanitary conditions among England's laboring classes, which argues that environment and disease are intimately linked, and that governments should be concerned with matters such as establishing municipal water supplies and sewage systems to improve public health.

1848: Great Britain's Public Health Act establishes the General Board of Health, which lays the groundwork for modern public health.

1849: The Croton Aqueduct Department forms in New York City to build a comprehensive sewer system for the city. Seventy miles are constructed by 1855, and by the 1890s New York City has 464 miles of sewers, more than any other American or European city except Chicago. Part of the motivation is recurrent cholera epidemics, including one in 1849 that causes 5,071 deaths (cholera is transmitted through fecal matter, hence keeping sewage out of the drinking water supply is crucial). The new sewer system proves effective as the last cholera epidemic in the city is in 1892 and causes fewer than 120 deaths.

[Page xx]1854: John Snow uses geographic analysis to trace the source of a cholera outbreak in London to a particular water pump, bolstering his theory that cholera is transmitted through water (long before the specific organism that causes cholera had been identified) and bolstering support for making the provision of clean drinking water a civic responsibility.

1863: The world's first subway opens in London, England.

1892: The Sierra Club, one of the most influential environmental organizations in the United States, is founded in San Francisco.

1894: New York City approves a referendum for a subway system to be constructed at public expense to reduce traffic congestion in the city streets. The first segment opens in 1902, and the entire system is in operation by 1908 (although it will be greatly expanded in years to come). It is the first in the world to have a four-track system (local and express lanes in both directions).

1894: Detroit's Potato Patches program establishes the first organized community garden program in the United States, promoting self-sufficiency, and providing food for the impoverished during an economic crisis.

1900: The Sanitary District of Chicago reverses the flow of the Chicago River, sending sewage and other pollutants into the Sanitary and Ship Canal, significantly improving the water quality in Lake Michigan.

1928: Large-scale use of geothermal power is initiated when a borehole is sunk in Reykjavik, Iceland. This system now provides hot water for 80 percent of the households in Reykjavik, as well as domestic heating.

1930: A thermal inversion in the Meuse Valley of Belgium traps pollutants from nearby industrial plants in the local atmosphere, causing about 60 deaths and many illnesses.

1931: Charleston, South Carolina, passes the nation's first zoning ordinance establishing historic districts in order to preserve older neighborhoods and the city's unique sense of place.

1941–1945: Gas rationing in the United States due to World War II encourages carpooling as a patriotic activity.

1952: London, England, experiences a thermal inversion in December that, combined with air pollution from automobiles, factories, and coal-burning furnaces, blankets the city in smog that is believed to have caused about 3,000 excess deaths.

1954: The U.S. Supreme Court rules in Berman v. Parker that city governments may use the principle of eminent domain to seize properties in areas considered to be blighted and redevelop them as part of an urban renewal campaign.

[Page xxi]1955: The Air Pollution Control Act of 1955 becomes the first federal legislation in the United States concerned with air pollution, although its scope is limited to providing funds for air pollution research.

1961: Jane Jacobs's The Death and Life of Great American Cities criticizes urban renewal policies (in particular those championed by Robert Moses in New York City) that destroy neighborhoods, favor automobiles over people, and ignore the benefits of the human-scale, pedestrian-friendly environments provided by many of the world's great historical cities.

1962: Community activists and historical preservationists succeed in preventing the destruction of Ghirardelli Square in San Francisco. This former chocolate factory becomes the first example of successful adaptive reuse, repurposing a historic structure.

1963: The Clean Air Act establishes a federal program within the U.S. Public Health Services and authorizes research into monitoring and controlling air pollution, making it the first federal legislation in the United States to deal with the control of air pollution.

1969: Scottish landscape architect Ian McHarg publishes Design With Nature, a landmark work on ecological planning.

1970: The Clean Air Act authorizes the development of U.S. state and federal regulations to limit emissions from both stationary (such as industrial) and mobile sources (such as automobiles).

1970: The New York City Traffic Department coins the term “gridlock” to describe traffic congestion, in particular when an intersection is blocked because cars moving in one direction cannot clear the intersection before the light turns red, blocking traffic attempting to move in the cross direction.

1970s: The term brownfield is coined to refer to abandoned industrial and commercial facilities (initially steel plants in the United States) that may be contaminated by hazardous waste such as chemical pollutants.

1971: A fire in the basement of an office building in Binghampton, New York, highlights the dangers of using PCBs (polychlorinated biphenyls) in construction when contaminated soot spreads throughout the building through the air conditioning ducts.

1972: The U.S. Congress passes the Coastal Zone Management Act, initiating a process of sustainable development of coastal zones.

1974: Curitiba, Brazil, develops the first bus rapid transit (BRT) system that uses buses on roads to provide services more typical of rail systems. Innovations for this type of bus system include providing a dedicated travel lane, permanent stations and stops, more efficient methods of boarding and fare collection, and relatively fewer stops placed further apart.

[Page xxii]1976: The Tax Reform Act encourages adaptive reuse in the United States by allowing faster tax write-offs for projects that recycle or restore historic properties.

1978: U.S. President Jimmy Carter declares Love Canal, a toxic waste dump in Niagara Falls, New York, a national emergency due to chemical pollution. Over 1,000 families are evacuated at public expense.

1978: New York City begins Operation Green Thumb to encourage community gardening. The city allows residents to use vacant lots for gardens for the nominal fee of $1 per year. By 1991 the city reports that there are over 500 community gardens in the city.

1980s: Staten Island (New York City) establishes the first successful Bluebelt, a system of local septic tanks, rather than an island-wide conventional storm water system.

1981: Seaside, Florida, often cited as the first New Urbanist development, is built on the model of traditional southern towns with narrow streets and alleys, and houses with porches and pitched roofs.

1981: A task force of experts from Colorado State University and the Associated Landscape Contractors of Colorado coin the term “xeriscape,” meaning landscaping that is water-efficient and bioregionally appropriate.

1983: The Environmental Protection Agency recommends that the residents of Times Beach, a small town in Eastern Missouri, evacuate due to dioxin contamination. The chemical was a contaminant in oil spread on the roads to control dust in the 1970s.

1984: Los Angeles reduces vehicle traffic by 50 percent in preparation for the Olympics through ride-sharing schemes and other measures, although the plan to reserve specific freeway lanes for cars carrying three or more passengers was abandoned.

1986: Chernobyl, Ukraine (formerly of the Soviet Union), is the site of the worst nuclear disaster in history. The amount of radiation released is estimated to be 100 times that of the atomic bombs dropped in 1945 on Hiroshima and Nagasaki.

1987: The United Church of Christ Commission for Racial Justice issues a study demonstrating that the location of toxic waste sites is more closely related to the race of neighborhood residents than to either income or social class.

1987: The infamous New York City “garbage barge” cruises the Atlantic and Gulf coasts looking for a dump that will accept the over 3,000 tons of commercial refuse it carries. Eventually the barge returns to New York where its cargo is incinerated, but the incident raises awareness of the growing problem of garbage disposal in America's cities.

1989: New York City enacts a broad recycling law (Local Law 19), in large part to reduce air pollution caused by the incineration of garbage. By 1996 the city claims that 41 percent of its refuse is diverted to recycling.

[Page xxiii]1989–1993: Water metering trials of 53,000 British households estimate that compulsory metering could reduce domestic water use by 11 percent. However, the trial also demonstrates that conservation effects may not last because consumers quickly become used to the presence of the water meter.

1991: Germany adopts stringent measures to reduce the quantity of garbage by requiring that manufacturers, distributors, and retailers collect and recycle all packaging waste from their products.

1992: The Earth Summit held in Rio de Janeiro results in the document “Agenda 21,” which calls for national governments to adapt strategies for sustainable development and to cooperate with nongovernmental organizations and other countries in implementing them.

1992: Mayor Richard M. Daley establishes a Department of the Environment for the city of Chicago, which undertakes the Brownfields Initiative to redevelop abandoned industrial areas, as well as projects such as tree planting to improve the aesthetic qualities of city streets.

1993: William Kunstler's The Geography of Nowhere: The Rise and Decline of America's Man-Made Landscape argues that urban sprawl has created a suburban environment that is ecologically destructive as well as counterproductive to normal human living.

1993: The International Coalition for Local Environmental Initiatives creates the Cities for Climate Protection network to support urban measures to reduce greenhouse gas emissions. It had more than 750 members in 2010.

1995: The Global Ecovillage Network is founded, providing an administrative home for those interested in creating intentional communities that are sustainable, support human development, and minimize human ecological impact.

1996: William Rees and Mathis Wakernagel develop the concept of the “ecological footprint,” which signifies all the resources used by a particular population or species in their book Our Ecological Footprint: Reducing Human Impact on the Earth.

1999: The Ecuadorian capital city of Bahía de Caráquez embarks on a campaign of rebuilding on principles of ecological sustainability following repeated damage from flooding and mudslides.

1999: The Congress for the New Urbanism estimates that seven percent of regional and superregional malls are grayfields (abandoned or underused commercial properties) with an additional 12 percent of U.S. malls likely to enter greyfield status by 2004.

2000: New York City introduces Green Building Tax Credits, which offer tax breaks to developers whose buildings meet energy efficiency standards.

[Page xxiv]2001: Bangkok begins enforcing a series of regulations intended to lessen the city's environmental impact and improve the health and welfare of its citizens. These measures include monitoring vehicle emissions, enforcing the use of covering sheets on trucks and construction sites, and providing free vehicle inspections and tune-ups.

2001: The U.S. Green Building Council founds the Green Building Certification Institute to certify Leadership in Energy and Environmental Design (LEED) professionals who are qualified to evaluate the sustainability of buildings.

2003: Great Britain institutes traffic congestion pricing, charging a daily rate for drivers to enter the central zone of London. The program is successful: Studies indicate that traffic in the affected area fell by 21 percent 2002–2006.

2003: Zipcars, the world's largest car sharing program, introduces hybrids to its Seattle fleet.

2003: A massive blackout in Ontario, Canada, and the eastern and midwestern United States affects an estimated 55 million people, and points out the vulnerability of the electrical power grid.

2003: Kansas City, Missouri, adopts a walkability plan intended to reduce automobile use and encourage walking. It includes plans to ensure safe routes for local children to walk to school, reversing decades of suburban development that assumed that any trip beyond the immediate neighborhood would be made by automobile.

2004: A study by SMARTRAQ, a land use research project conducted by Georgia Tech University, finds that residents who live in parts of Atlanta, Georgia, characterized by urban sprawl drive 40 percent more on weekends and 30 percent more during the week than people who live in areas of the city more conducive to walking.

2005: The E.U. Emission Trading Scheme, a carbon-trading scheme involving 25 of the then-27 European Countries, officially begins.

2005: The Brookings Institute issues a report stating that the average partial carbon footprint of people living in metropolitan areas was 14 percent lower than that of the U.S. population at large. The reasons cited include less automobile use, compact housing, and mixed-development neighborhoods.

2005: The U.S. Conference of Mayors endorses the U.S. Mayors Climate Protection Agreement, which commits mayors to working to reduce greenhouse emissions in their cities. As of 2009, 969 mayors representing nearly 85 million people signed the agreement.

2007: Barcelona begins a bike-sharing program in which members pay an annual fee plus a small charge for each half-hour of bicycle use. The program begins with 30,000 subscribers and 400 bicycles, and has grown to 186,000 subscribers and 6,000 bicycles.

[Page xxv]2007: New York City passes Local Law 86, more commonly known as the Green Buildings Act, which requires that new municipal buildings and renovations and additions to existing buildings meet LEED sustainability standards.

2007: San Francisco, California, bans polystyrene foam (Styrofoam) containers for takeout food, requiring that containers used for that purpose be compostable or recyclable.

2008: Gasoline prices go over $4 per gallon in the United States, encouraging the use of public transportation, as well as alternatives such as biking and walking.

2008: SustainLane chooses Portland, Oregon, for the second year in a row as the greenest of the green cities. Fifty U.S. cities were evaluated on 16 criteria related to urban sustainability.

2009: San Francisco, California, passes the most stringent recycling and composting ordinance in the United States. Several other cities have mandatory recycling, but San Francisco is the first to require composting as well.

2009: Sydney, Australia, holds a one-hour citywide blackout in March to raise awareness of global warning and encourage conservation.

2009: The European Commission names Stockholm, Sweden, first European Green Capital.