United Nations Environment Programme in the context of "Resource efficiency"

Nairobi (abbreviated as NBO, NBI or NRB) is the capital and largest city of Kenya, located in the south-central part of the country. As of 2024, it has a population of 4.8 million and a metropolitan population of 5.7 million, making it the 11th most populous city in Africa. Nicknamed the “Green City in the Sun,” Nairobi is uniquely notable for being the only capital city in the world that hosts a national park within its boundaries, and its name originates from the Maasai phrase Enkare Nyirobi, meaning “place of cool waters."

As the capital of the country, Nairobi is home to the Kenyan Parliament Buildings, the State House and the Supreme Court Building. It is the major financial and economic hub of East Africa, hosting thousands of Kenyan businesses and international companies and organisations, including the United Nations Environment Programme (UN Environment) and the United Nations Office at Nairobi (UNON). The Nairobi Securities Exchange (NSE) is one of the largest stock exchanges in Africa and the second-oldest exchange on the continent. It is Africa's fourth-largest stock exchange in terms of trading volume, capable of making 10 million trades a day. Nairobi is considered a global city and was ranked as a "Beta World City" by the Globalization and World Cities Research Network as of 2024.

Bike lanes (US) or cycle lanes (UK) are types of bikeways (cycleways) with lanes on the roadway for cyclists only. In the United Kingdom, an on-road cycle-lane can be firmly restricted to cycles (marked with a solid white line, entry by motor vehicles is prohibited) or advisory (marked with a broken white line, entry by motor vehicles is permitted). In the United States, a designated bicycle lane (1988 MUTCD) or class II bikeway (Caltrans) is always marked by a solid white stripe on the pavement and is for 'preferential use' by bicyclists. There is also a class III bicycle route, which has roadside signs suggesting a route for cyclists, and urging sharing the road. A class IV separated bike way (Caltrans) is a bike lane that is physically separate from motor traffic and restricted to bicyclists only.

Research shows that separated bike lanes improve the safety of bicyclists, and either have positive or non-significant economic effects on nearby businesses. The United Nations Environment Programme says there ought to be at least ten times more bike lanes by 2030 than there were in 2020.

The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to "provide governments at all levels with scientific information that they can use to develop climate policies". The World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) set up the IPCC in 1988. The United Nations endorsed the creation of the IPCC later that year. It has a secretariat in Geneva, Switzerland, hosted by the WMO. It has 195 member states who govern the IPCC. The member states elect a bureau of scientists to serve through an assessment cycle. A cycle is usually six to seven years. The bureau selects experts in their fields to prepare IPCC reports. There is a formal nomination process by governments and observer organizations to find these experts. The IPCC has three working groups and a task force, which carry out its scientific work.

The IPCC informs governments about the state of knowledge of climate change. It does this by examining all the relevant scientific literature on the subject. This includes the natural, economic and social impacts and risks. It also covers possible response options. The IPCC does not conduct its own original research. It aims to be objective and comprehensive. Thousands of scientists and other experts volunteer to review the publications. They compile key findings into "Assessment Reports" for policymakers and the general public; Experts have described this work as the biggest peer review process in the scientific community. The IPCC was the first of three global science policy panels to be established, followed by and IPBES (Intergovernmental Platform on Biodiversity and Ecosystem Services), established in 2012 and the Intergovernmental Science-Policy Panel on Chemicals, Waste and Pollution (ISPCWP) established in 2025.

Green building certification systems are a set of rating systems and tools that are used to assess a building or a construction project's performance from a sustainability and environmental perspective. Such ratings aim to improve the overall quality of buildings and infrastructures, integrate a life cycle approach in its design and construction, and promote the fulfillment of the United Nations Sustainable Development Goals by the construction industry. Buildings that have been assessed and are deemed to meet a certain level of performance and quality, receive a certificate proving this achievement.

According to the Global Status Report 2017 published by United Nations Environment Programme (UNEP) in coordination with the International Energy Agency (IEA), buildings and construction activities together contribute to 36% of the global energy use and 39% of carbon dioxide (CO₂) emissions. Through certification, the associated environmental impacts during the lifecycle of buildings and other infrastructures (typically design, construction, operation and maintenance) could be better understood and mitigated. Currently, more than 100 building certifications systems exist around the world. The most popular building certification models today are BREEAM (UK), LEED (US), and DGNB (Germany).

A green economy is an economy that aims at reducing environmental risks and ecological scarcities, and that aims for sustainable development without degrading the environment. It is closely related with ecological economics, but has a more politically applied focus. The 2011 UNEP Green Economy Report argues "that to be green, an economy must not only be efficient, but also fair. Fairness implies recognizing global and country level equity dimensions, particularly in assuring a Just Transition to an economy that is low-carbon, resource efficient, and socially inclusive."

A feature distinguishing it from prior economic regimes is the direct valuation of natural capital and ecological services as having economic value (see The Economics of Ecosystems and Biodiversity and Bank of Natural Capital) and a full cost accounting regime in which costs externalized onto society via ecosystems are reliably traced back to, and accounted for as liabilities of, the entity that does the harm or neglects an asset.

Agbogbloshie was the nickname of a commercial district on the Korle Lagoon of the Odaw River, near the center of Accra, Ghana's capital city in the Greater Accra region, before it was demolished by the Ghanaian government in 2021. Near the slum called "Old Fadama", the Agbogbloshie site became known as a destination for externally generated automobile and electronic scrap collected from mostly the Western world. It was a center of a legal and illegal exportation network for the environmental dumping of electronic waste (e-waste) from industrialized nations. The Basel Action Network, a charitable non-governmental organization based in Seattle, has referred to Agbogbloshie as a "digital dumping ground", where millions of tons of e-waste were processed each year.

The most exhaustive study of the trade in used electronics in Nigeria, funded by the United Nations Environment Programme (UNEP) and the Basel Convention, revealed that, out of 540,000 tonnes of informally processed waste electronics, 52% of the material was recovered.

The World Database on Protected Areas (WDPA) is compiled and managed by the World Conservation Monitoring Centre, an executive agency of the United Nations Environment Programme. It uses the IUCN and CBD definitions of protected areas to determine whether a site should be included in the WDPA. The extent to which each area and the resources within are protected can vary significantly.

The largest protected areas – those exceeding an area of 250,000 square kilometres – are listed below in order of total area protected. All are marine protected areas except for Northeast Greenland National Park – which is mostly terrestrial but also has a marine component – and three entirely terrestrial biosphere reserves in Brazil. Protected areas with multiple coterminous or overlapping designations (e.g. Northeast Greenland National Park and the corresponding Biosphere Reserve) are listed only once.