Climate Change

Climate change refers to long-term shifts in temperature and weather patterns affecting Earth. Shifts can be natural, but since the 1800s, human activities have been the main driver of climate change. A significant cause of climate change is the burning of fossil fuels like coal, oil and gas which generates greenhouse gas emissions.

Greenhouse gases both absorb and emit the sun’s radiation, causing the “greenhouse effect” – the gases act like a blanket wrapped around Earth, trapping the sun’s heat rather than letting it escape into space, and raising the planet’s temperatures.

Water vapour, carbon dioxide, nitrous oxide, methane and ozone are the primary greenhouse gases in Earth’s atmosphere. There are also others that are entirely human-made such as halocarbons and other chlorine- and bromine-containing substances, sulphur hexafluoride, hydrofluorocarbons and perfluorocarbons.

Fossil fuel use in cars or to heat buildings contribute to climate change by releasing carbon dioxide and methane. Clearing land and cutting down trees can also release carbon dioxide into the atmosphere. Agriculture, oil and gas operations are major sources of methane emissions.

The impact of human-driven (anthropogenic) changes to the structure and functioning of Earth, including the climate system, is so extreme that it has led to the suggestion we have entered a new epoch. The Anthropocene is thought to be distinct from the Holocene. The Holocene is the name given to the prior 11,000 or so years of Earth’s history i.e. since the end of the “ice age”. The mid-20th Century has been proposed as the most appropriate starting date for the Anthropocene, although discussions continue.

Healthy ecosystems and a healthy planet are preconditions for flourishing life on Earth. The latest IPCC synthesis report shows that climate change is a threat to both human well-being and planetary health, and there is a rapidly closing window of opportunity to secure a liveable and sustainable future for all (IPCC, 2023).

Climate change is leading to more areas prone to flooding, and more areas prone to droughts, threatening homes, businesses and nature. Heavily modified rivers are less resilient and have lost their natural ability to retain water in both droughts and floods. By re-connecting streams and rivers to floodplains, restoring a formerly meandering course and other natural storage areas, and enhancing the quality and capacity of wetlands, river restoration increases natural storage capacity and reduces flood risk.

River restoration also improves biodiversity and creates more natural spaces that act as refuges for people and wildlife from higher temperatures. Climate change and biodiversity loss are one - each stressor contributes to and exacerbates the effects of the other. Strengthening biodiversity in all systems will support long-term climate stabilization (Pörtner et al., 2023).

• Novel research into impacts of biodiversity and climate crises
• IPCC. (2023). Synthesis report of the IPCC sixth assessment report (AR6)
• United Nations - What is Climate Change?
• European Centre for River Restoration. (n.d.). River restoration and biodiversity
• Pörtner et al. (2023). Overcoming the coupled climate and biodiversity crises and their societal impacts. Science.