The Urgency of Climate Change

Climate change is not a distant threat, but a present reality that affects every region of the world and every aspect of human well-being. The latest report from the Intergovernmental Panel on Climate Change (IPCC) provides a comprehensive and sobering assessment of the current state of the climate system, the projected future changes, and the risks and opportunities for adaptation and mitigation.

The report, released in August 2021, is based on thousands of peer-reviewed scientific studies and approved by 195 member governments of the IPCC. It confirms that human activities, mainly the burning of fossil fuels, are the main cause of global warming since the pre-industrial era, and that this warming has already reached about 1.1°C above the 1850-1900 average. The report warns that unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to 1.5°C or even 2°C above pre-industrial levels will be beyond reach.

The consequences of further warming are dire for people and nature. The report shows that climate change is already affecting every aspect of the Earth's system, from the oceans to the land, from the poles to the tropics, and from the weather to the biosphere. Many of these changes are unprecedented in thousands or even millions of years, and some are irreversible on human timescales, such as the melting of ice sheets and the rise of sea levels.

Some of the impacts of climate change that are already being felt include:

- More frequent and intense heat waves, droughts, wildfires, floods and storms. For example, in 2020, a record-breaking heat wave in Siberia triggered massive wildfires that released more carbon dioxide than in any year since satellite records began in 2003. In 2021, extreme rainfall caused devastating floods in Germany, Belgium, China and India, killing hundreds of people and displacing millions more.

- Reduced food security and water availability, especially in vulnerable regions. For example, in 2019, a severe drought in southern Africa affected more than 45 million people across 14 countries, leading to crop failures and food shortages. In 2020, a locust outbreak triggered by unusually warm and wet conditions in East Africa threatened the food security of more than 25 million people across 10 countries.

- Increased risks to human health from heat stress, air pollution, infectious diseases and mental stress. For example, in 2018, an estimated 296,000 people died prematurely due to exposure to fine particulate matter (PM2.5) from fossil fuel combustion. In 2019, a record-breaking dengue fever outbreak affected more than 3 million people across Latin America and Southeast Asia, linked to higher temperatures and rainfall variability.

- Loss of biodiversity and ecosystem services, such as pollination, carbon storage and coastal protection. For example, in 2016-2017, a global coral bleaching event caused by marine heat waves killed about half of the coral cover on the Great Barrier Reef. In 2020-2021, deforestation rates in the Amazon rainforest increased by 17% compared to the previous year, driven by land use change and wildfires.

- Displacement and migration of people due to climate hazards or resource scarcity. For example, in 2019-2020, more than 30 million people were newly displaced by disasters triggered by natural hazards across 149 countries and territories. In 2020-2021, more than 5 million people were affected by drought-induced displacement in Afghanistan.

- Increased conflicts and violence over scarce resources or unequal impacts. For example, in 2019-2020, climate variability and change contributed to exacerbating existing conflicts or triggering new ones in countries such as Syria, Yemen, Mali and Ethiopia.

- Reduced economic growth and increased poverty and inequality. For example, in 2018-2019, climate-related disasters caused an estimated $210 billion in direct economic losses globally. In 2020-2021, climate change aggravated the socio-economic impacts of the COVID-19 pandemic.

The report also highlights that some impacts of climate change may be abrupt or irreversible, such as the collapse of ice sheets, the dieback of forests, or the activation of tipping points in the climate system. These could lead to large-scale and potentially catastrophic consequences for human and natural systems.

The report emphasizes that there is still time to avoid the worst outcomes of climate change,

but only if we act urgently and decisively to reduce greenhouse gas emissions and enhance resilience to climate impacts. The report shows that every fraction of a degree of warming matters for reducing risks and increasing benefits. The report also shows that there are multiple pathways to achieve net-zero emissions by mid-century, which is necessary to limit warming to 1.5°C or well below 2°C. These pathways involve rapid and deep transformations in all sectors of society, such as energy, transport, industry, agriculture, and land use.

The report also stresses that adaptation and mitigation are not only necessary but also beneficial for human well-being and sustainable development. Adaptation can reduce the negative impacts of climate change and enhance the positive ones, while mitigation can avoid further warming and its associated risks. Both can also create co-benefits for other societal goals, such as improving health, reducing poverty, enhancing equity, protecting nature, and fostering innovation.

The report concludes that climate change is a threat to human well-being and planetary health that requires urgent and coordinated action from all levels of society. The report also offers hope that we can still shape our future by choosing actions that are consistent with our values and aspirations.