OBSERVER: Humans and where they live – insights from the Atlas of the Human Planet 2024
OBSERVER: Humans and where they live – insights from the Atlas of the Human Planet 2024
evan
Fri, 06/12/2024 – 15:06
In just under half a century, the global population has doubled from four billion in 1975 to eight billion in 2022. This rapid growth has transformed the planet, driving the expansion of the built-up surface—houses, buildings, parking lots etc.—at an unprecedented rate. Yet, this development has been uneven, with some regions undergoing more dramatic urban sprawl than others. Understanding how both populations and built-up areas evolve over time is essential to grasping humanity’s impact on Earth.
On 30 October, the European Commission’s Joint Research Centre (JRC) unveiled the Atlas of the Human Planet 2024. This document, based on data from the Global Human Settlement Layer (GHSL) of the Copernicus Emergency Management Service (CEMS), provides a 50-year perspective on global population growth and urbanisation trends. In today’s Observer, we’ll explore some highlights from the Atlas, including how settlement data can help support disaster risk reduction and response, shape sustainable policies, and guide global development.
Mapping human presence with open data
To tackle today’s sustainable development challenges and prepare for future ones, understanding where people live and work is of utmost relevance. The Global Human Settlement Layer (GHSL), a product of the Exposure mapping component of CEMS, contributes to this effort by mapping human presence on the planet over time and providing global spatial data.
To develop GHSL datasets, the Joint Research Centre extracts information about built-up areas from Copernicus Sentinel-1 and Sentinel-2 satellites images and combine them with national census data to develop population density grids. These grids are then used to map settlement types, classifying areas into cities, towns and semi-dense zones, or rural regions.
GHSL products are provided as open and free data. These include global coverage datasets described in the GHSL Data Package 2023, pan-European built-up layers such as the European Settlement Map and analytical data, including the Urban Centre Database.
Highlights from the Atlas of the Human Planet 2024
The Atlas of the Human Planet 2024, based on GHSL and other data sources, highlights a significant increase in both population and built-up areas worldwide. Today, around 3.5 billion people live in cities. This is three times more than in 1975, with nearly half of the global population now calling urban areas home.
Of the world’s 11,000 cities, megacities, defined as those with populations exceeding ten million, stand out as symbols of rapid urbanisation. Asia and the Americas host the majority of these megacities. Asia is home to the most populous ones, including Jakarta, Tokyo, Shanghai, and Delhi, each with populations of over 25 million.
Urban populations have more than doubled since 1975, driving significant expansion of cities. However, other types of settlements, such as populated rural areas and semi-dense areas, have also seen significant growth. While the global population doubled between 1975 and 2020, the built-up surface almost tripled. This rapid expansion of built-up surfaces shows the increasing pressures of urbanisation and population growth, reshaping the planet to accommodate humanity’s evolving needs.
GHSL data for disaster risk reduction and emergency management
Besides helping us study settlements worldwide, GHSL products are also important tools for preparing for and managing disasters. GHSL data plays a key role in assessing risks, vulnerability and exposure and supporting crisis managers during response efforts, and planning recovery. For example, after the devastating 2023 earthquake in Türkiye and Syria, GHSL data was used to help rescue teams understand the affected cities’ built-up areas, building heights, and floor space. These insights also supported the estimation of debris from destroyed buildings and guided recovery planning.
GHSL data is equally valuable for responding to flood events. During the catastrophic floods in Pakistan between June and October 2022, which claimed 1,739 lives and caused significant economic losses, the CEMS On-Demand Mapping component was activated to monitor and assess the extent of the flooding across various cities. It provided mapping products to assess the severity of the disaster, the damage caused to infrastructure, and the number of people affected, based on the population and built-up data provided by GHSL.
GHSL data for policymaking and planning
GHSL information and the insights it provides into regional dynamics are also crucial for policymaking. GHSL products help in the implementation of EU regional urban policies and key international frameworks, such as the Sustainable Development Goals (SDGs) and the Sendai Framework for Disaster Risk Reduction. In particular, the Sendai Framework was the first major agreement of the post-2015 development agenda and provides UN Member States with concrete actions to protect development gains from the risk of disasters.
In this context, the Degree of Urbanisation methodology, endorsed by the UN Statistical Commission in 2020, is applied to GHSL data to classify cities, towns, and rural areas. This methodology is useful for monitoring the SDGs, as well as supporting disaster risk reduction, and environmental research. The GHSL team also provides training on the Degree of Urbanisation to help users effectively apply it to their own data, further supporting policy decisions and the achievement of SDG 11.
To support sustainable urbanisation initiatives, such as those aimed at identifying and monitoring vulnerable areas, the Urban Centre Database developed by the GHSL team is also an valuable tool. This database provides data on cities worldwide, covering aspects such as population growth, environmental impacts of urbanisation, and infrastructure development, helping stakeholders monitor how cities change over time and make informed urban policy decisions.
GHSL data tracks the evolution of human settlements—urban, rural, and semi-dense—providing key information which helps shape sustainable policies, support disaster risk reduction and emergency response, and inform strategic urban planning worldwide. The Atlas of the Human Planet 2024 demonstrates how GHSL data can be synthesised to deliver powerful insights into global population growth and urbanisation trends.
The complete Atlas of the Human Planet 2024 can be viewed and downloaded here.
Fri, 06/12/2024 – 12:00
