Sweden has had a prominent role in the natural sciences since the 18th century, with Carl Linnaeus founding systematic biology, and Anders Celsius inventing the 100-degree temperature scale. In 1896, physicist Svante Arrhenius described the greenhouse effect. Since 1901, Stockholm hosts the Nobel Prize ceremony. The rise of Nordic nationalism in the 19th century included appreciation of nature and outdoor life as a pastime; and the sparse population allowed the right to roam. With vast distances, Sweden has had a love story with the automobile, with Volvo, Saab and Scania as well-known brands. While Swedish cars and trucks have traditionally been heavier than other European brands, they are now pioneering fuel efficiency. Stockholm was redeveloped during the 1960s with an extensive system of highways (and sprawling suburbs) which was brought to a halt in the early 1970s with a rising environmentalist movement, as well as the 1973 oil crisis. Since the 2010s, car lanes and parking lots have been reduced to make room for cyclists and pedestrians.
Sweden has no domestic fossil fuels (except peat) and has been phasing out coal and oil for strategic reasons already since the mid-20th century. As the climate agenda has become important, Sweden has a realistic aim for a carbon-free economy.
Stockholm, just as other large cities, used to be troubled by sewage well into the mid-20th century, and later by industrial pollution and vehicle emissions. Today the air is famously clean, and the water in lake Mälaren is good enough to drink.
While Stockholm has several airports nearby, a greener approach would be a train from Oslo or Copenhagen; see Rail and bus travel in Sweden. Stockholm can also be reached by sailing boat through Stockholm archipelago; see boating in the Baltic Sea.
Urban cycling is a good method to get around Stockholm, at least when weather is decently warm; see Cycling in Sweden. The bicycle lane system has been expanded during the 2010s. The city has had a bike rental system as well as electric scooter operators; as of 2020 their outlook is uncertain.
Cars are subject to congestion tax, and some parts of the inner city require Euro 5 or higher emission standard (see Driving in Sweden). Taxis are rather expensive, and do not follow a fixed price. Driving in Stockholm is rarely necessary, in any case.
- 1 Slussen. Slussen literally means "the sluice"; referring to the lock that drains the freshwater lake Mälaren 70 centimetres down to the brackish Baltic Sea, and used to be one of Sweden's most important commerce hubs. Over the centuries, Slussen has grown to a complex junction for ships, trains, cars and public transport, with Europe's first cloverleaf interchange in the 1930s. The interchange was torn down in the 2010s to make more room for pedestrians and cyclists. As of 2020, renovation has closed down much of the area, with re-routed walkways, and crowds at rush hour.
- 2 Mynttorget (Gamla stan). The square next to the parliament building is the location of public protests, including Greta Thunberg's climate strike.
- 3 Royal Palace (Kungliga Slottet). Built between 1697 and 1754, the Royal Palace is the official residence of the king of Sweden. The reigning king Carl XVI Gustaf (who lives in Drottningholm in Ekerö) has För Sverige i tiden ("For Sweden, with the times") as his motto; as an avid environmentalist, he has had solar panels installed on the palace roof.
- 4 Kungsträdgården. The name "the King's Garden" bears witness of the original function as a closed-off royal park, open to the public only since the 18th century. Today it is used for festivals and other public events. Out of several redevelopments of the park, the most controversial was a metro exit, which was to be built in 1971, requiring the destruction of thirteen elm trees. Public protests forced the government to back down, and relocate the exit to a nearby building.
- 5 Environmental obelisks (Miljöobelisker). Since 1994, these obelisks provide a live bar chart of pollution and other parameters for air and water in Stockholm.
- 6 Skansen. Founded in 1891, Skansen is the world's oldest open-air museum, containing a zoological garden specializing in Nordic fauna, such as moose, reindeer, voar, bear, wolf, lynx and wolverine, with information about their conservation status. It features over 150 historic buildings from previous centuries, relocated from all parts of Sweden. Skansen has been paramount in species conservation, especially for the European bison. An addition from 2018 is an aquarium which displays the environmental threats to the Baltic Sea.
- 7 Stockholm Gas Works (Östermalm). Once a dirty industrial facility which processed imported coal and oil to hydrocarbon fuel gas. During the 2010s, the contaminated ground has been sanitized, making place for a new urban district. The industrial buildings remain. The last coal power station is to be shut down in 2020.
- 8 Värtaverket (Östermalm). A power plant opened in 1903. It used coal for much of its history, until the coal boilers were finally shut down in 2020. Today, all fuels are renewable.
- 9 Henriksdal sewage treatment plant. A state-of-the-art sewage treatment plant which extract biogas for vehicles.
- 10 Hammarby Sjöstad (Södermalm). A former industrial slum which was torn down in 2002 to make place for a new district, intended to be a hallmark of energy efficiency and recycling.
- Stockholm Transport Museum (Stockholms spårvägsmuseum). A museum of Stockholm's public transportation system, with an emphasis on trams, to open in early 2021.
- 11 Swedish Museum of Natural History (Naturhistoriska riksmuseet), Frescativägen 40 (T Universitetet and then bus 40 or 540). Tu-W F 10:00-19:00, Th 10:00-20:00, Sa Su 11:00-19:00. The museum's displays animals, plants, fungi, minerals and fossils from all continents, some acquired during the voyages of James Cook. Feature exhibits of evolution, the polar areas, and Scandinavian nature.
- 12 R1 Reactor Hall. Sweden's first experimental nuclear reactor. As in other countries, nuclear technology has been controversial in Sweden. Sweden's Cold War non-alignment policy led to a nuclear weapons program, which was just a few grams of plutonium short of a live bomb test; but since the 1960s the country has adhered to the non-proliferation treaty. A national referendum in 1980 led to the unambigous result to phase out nuclear power in Sweden; while the proposed deadline was 2010, the country still has three active nuclear power plants in 2020, supplying nearly half of the country's electricity. Access only during special events.