Global near-surface temperatures have reached record highs, and with 98% certainty one of the next five years being one of the warmest ever on record. This increase can be attributed to greenhouse gases trapping heat in our atmosphere as well as naturally occurring El Nino events causing an El Nio event.
This update uses the attribution assessment approach of WGI AR6. It leads to similar remaining carbon budget estimates on decadal timescales but starts five years later (Supplement, Sect. S7).
Global Temperature
Recent years were among the warmest ever recorded, and 2023 looks set to follow suit with an estimated 98-percent chance that one or more of the next five years will set new records for warmth according to World Meteorological Organization (WMO).
WMO states that while La Nina conditions of recent years temporarily moderated longer-term global temperature increases, an El Nino event is forecasted for this year – typically resulting in even warmer global temperatures than 2023! So it could happen even faster.
A warming planet increases the risks of heatwaves and wildfires while hastening glacier melting in remote areas. Flooding will ensue in certain places while drought will prevail elsewhere, making it harder for people to grow food or locate water supplies; this situation is likely to become especially acute in developing nations that produce the least greenhouse gas emissions.
Sea Level
Sea level refers to the elevation of sea surface relative to land and is affected by local weather conditions such as tides and atmospheric pressure; additionally it reacts to long-term climate change.
Melting glaciers and ice sheets, along with thermal expansion of ocean water as it warms, contribute to sea level rise. As global warming accelerates, so will sea levels.
Sea level rise is an immense threat for coastal communities worldwide, including many of the world’s major cities. Even small amounts of rise could inundate islands, coasts and low-lying areas with sand and mud, erode coastlines, disturb ecosystems and force people to relocate or change lifestyles; it could disrupt food production in Nile and Mekong river deltas and disrupt production altogether. UN Secretary General Antonio Guterres warned of its negative ramifications for biodiversity, food security and human rights of millions of people worldwide.
Extreme Weather Events
Understanding the link between human-caused climate change and extreme weather events – whether they involve heat waves that kill, heavy rainfall that floods or drought – and these events is critical for elected officials and business leaders who must make long-term investments and infrastructure choices. Yet accurately estimating both immediate and longer-term economic harm from extreme weather events can be challenging when scientific methods change rapidly.
Scientists now possess an effective tool for examining these impacts: “attribution.” Using real world observations and climate models, scientists use “attribution” to ascertain whether an event or trend would have taken place without human interference; increasingly often this research finds clear fingerprints of impact.
Scientists discovered that, in terms of Oregon and Washington heat waves that affected hundreds of western Canadian deaths at the end of June 2021, their existence would have been nearly impossible without climate change’s influence. As depicted below in pie chart form, climate change made certain events or trends more likely or severe (red), less likely or severe (orange), or had no discernible influence (blue); whilst 9 % had insufficient data to reach reliable conclusions.
Adaptation
Every degree of global warming magnifies climate risks such as water scarcity, desertification and extreme heat waves. To effectively address these threats, adaptation must play a vital role in managing them – thus becoming one of the cornerstones of Paris Agreement’s approach.
There are multiple, cost-effective adaptation solutions. Some are natural based, like protecting and restoring ecosystems or improving road surface quality for higher temperatures; others can include building flood defences, installing early warning systems for cyclones or switching to drought-tolerant crops – which also has many other co-benefits such as protecting biodiversity, improving water security, or increasing food productivity.
Governments can facilitate an equitable transition by crafting their adaptation strategies to more evenly distribute costs and benefits among the most vulnerable to climate change, including those most dependent on social protection programs for vulnerable groups. Such measures could include including adaptation into policies at an early stage or adapting social protection programs to address vulnerabilities more directly; inclusive decision-making processes or strengthening resilience efforts through the NAP Expo 2023 is an opportunity for Parties to learn more about such tools of adaptation as well as others that exist.