Human well-being and the health of the planet are endangered by the threat posed by global warming, increasing greenhouse gas emissions and insufficient efforts to contain them. Many of the effects of climate change (attributed “unequivocally” to human activities) are irreversible; that is why it is key to mitigate it to prevent further damage. In this sense, “a substantial reduction in the general use of fossil fuels” responsible for these gases is key. In fact, “there are multiple feasible and effective options to reduce greenhouse gas emissions and adapt to human-caused climate change. And now, in addition, they are available”. This is indicated by the scientists of the UN Panel on Climate Change (IPCC), which has finally approved a summary document of the sixth evaluation of climate change, which summarizes all the knowledge of this science since the Paris Agreement (2015).
In 2018, the IPCC highlighted the unprecedented scale of the challenge required to halt 1.5°C warming. Five years later, that challenge has become even greater due to the continued increase in greenhouse gas emissions.
The pace and scale of climate action plans are insufficient to tackle climate change, say scientists.
More than a century of burning fossil fuels, as well as uneven and unsustainable use of energy and land, has led to global warming of 1.1°C above pre-industrial levels. a substantial reduction in the overall use of fossil fuels.
This has resulted in more frequent and intense proven extreme weather events, causing increasingly dangerous impacts on nature and people in all regions of the world.
The report detects an “unequivocal” human influence on the warming of the atmosphere, the seas and on land. The sea level has risen 0.2 meters between 1901 and 2018. But the rise is accelerating: it goes from 1.3 millimeters a year between 1901 and 1971 to 1.9 millimeters between 1971 and 2006, and up to 3.7 millimeters since from 2006 to 2018.
Human influence has been seen as the common thread behind these increases since at least 1971. Other evidence is observed changes such as heat waves, heavy rainfall, droughts, and tropical cyclones. The degree of certainty in the attribution of this human influence “has strengthened” since the previous IPCC report (2014).
It is estimated that approximately 3.3 to 3.6 billion people live in areas that are highly vulnerable to climate change. The increasing events of extreme weather and climate, with serious impacts in many communities (Africa, Asia, South America, small islands…) have exposed millions of people to acute food insecurity. Between 2010 and 2020 human mortality caused by floods, droughts and storms was 15 times higher in highly vulnerable regions compared to low vulnerability regions.
Climate change has caused substantial damage and increasingly irreversible losses in ecosystems (terrestrial, freshwater, frozen areas and marine ecosystems).
Hundreds of losses of local species have occurred due to the increase in the magnitude of episodes of extreme heat, with massive mortality events registered in the sea and on the land surface.
In all regions, the increase in extreme heat events has resulted in varying degrees of human mortality and morbidity.
The incidence of weather-related and food and waterborne diseases as well as the incidence of vector-borne diseases have also increased)
Climate-induced food and water insecurity is expected to increase with increasing warming.
The report, adopted during a week-long session in Interlaken, Switzerland, highlights the loss and damage we are already experiencing and will continue into the future, particularly affecting the most vulnerable people and ecosystems.
“Climate justice is crucial because those who have contributed the least to climate change are disproportionately affected,” said Aditi Mukherji, one of the 93 authors of this Synthesis Report, the final chapter of the Panel’s sixth assessment.
“Almost half of the world’s population lives in regions highly vulnerable to climate change. In the last decade, deaths from floods, droughts and storms were 15 times higher in highly vulnerable regions,” adds the 37-page summary document for policy makers.
Meanwhile, containing warming to 1.5 °C above pre-industrial levels (or even slowing it down to 2ºC) means “taking immediate action that involves deep, rapid and sustained reductions in greenhouse gas emissions or this very decades. However, the climate action plans announced by governments (assuming they are met) lead to a warming of 2.8ºC by 2100.
Limiting warming to 1.5 ºC requires greenhouse gas reductions of 43% by 2030 compared to 2019; and if the goal set is that it does not cross the threshold of 2 ºC, then it would be necessary to reduce them by 21% with a path destined to approach climate neutrality by 2050.
The warming scenarios drawn by climate models for the end of the century (2081-2100) point to temperature rises of 1.4 ºC, 2.7 ºC and 4.4 ºC depending on the scenarios (low emissions, medium emissions or high emissions). .
The effects of these contrasting scenarios are discernible. Compound phenomena of heat waves and droughts will become more frequent.
“Extreme 100-year surge events are expected to occur at least annually at more than half of all tide gauge locations.”
The expected near-term hazards and risks include an increase in heat-related human mortality and morbidity, foodborne, waterborne, and vector-borne diseases, and mental health problems.
There is also a high degree of certainty of flooding in cities and coastal and other low-lying regions, as well as loss of biodiversity in terrestrial, freshwater and ocean ecosystems, and decreased food production in some regions.
The risks and projected adverse impacts and loss and damage related to climate change will increase with each increase in global warming-
The IPCC highlights that some future changes are inevitable and/or irreversible, although they may be limited with sustained reductions in global greenhouse gas emissions. The probability of an abrupt and/or irreversible change occurring increases as global warming worsens.
In the worst-case scenario (high emissions), sea level could rise by as much as 0.63 centimeters to 1.01 meters by 2100. In the next 2,000 years, mean global sea level may rise by 2 to 3 meters if the heating is limited to 1.5 ºC and up to 6 m if it is contained by 2 ºC more.
The press summary prepared by the IPCC (with government representatives) highlights the need for a development model that comprehensively addresses the response to climate change.
This implies that the measures adopted must lead to gas reductions and at the same time offer broader and more global benefits.
Delaying the action increases the costs while accelerating it brings co-benefits. For example: access to energy and clean technologies and active mobility reduce emissions and at the same time improve people’s health (electrification, walking, cycling) as well as diet changes towards a healthier diet. These costs would be approximately equal to, or possibly even greater than, the costs of reducing or avoiding emissions.
“Decisions made in the coming years will play a fundamental role in deciding our future and that of future generations,” says the press summary.
Any transition in the climate system requires achieving “deep emissions reductions” and adaptive transformations unprecedented on their scale.
This transition requires the implementation of low or null (zero) emission technologies, changes in product design, transformations of socio-cultural and behavioral values, greater efficiency and technological adoption; social protection, climate services and ecosystem restoration.
In the energy system, this implies: a substantial reduction in the general use of fossil fuels, opening the door to a carbon capture and storage system, electrification with systems that emit CO, and energy efficiency saving policies.
In the field of transport, sustainable biofuels, low-emission hydrogen and its derivatives (including ammonia and synthetic fuels) can help mitigate CO emissions from shipping, aviation and heavy trucking. However, improvements in production processes and cost reductions are required.
Sustainable biofuels may offer additional mitigation benefits in road transport in the short to medium term, although the degree of certainty is rated only “medium” here.
Electric vehicles powered by electricity with low greenhouse gas emissions have great potential to reduce ground transportation.
Similarly, advances in battery technologies could facilitate the electrification of heavy-duty trucks and complement conventional electric rail systems (“medium” confidence).
The environmental footprint of battery production and growing concerns about critical minerals can be addressed with “material and supply diversification strategies, energy and material efficiency improvements, and circular material flows (“medium confidence”)
To be effective, these choices must be rooted in our diverse values, worldviews, and knowledge, including indigenous knowledge and local knowledge.
This approach will facilitate climate resilient development and allow for locally appropriate and socially acceptable solutions.
“The largest welfare gains could come from prioritizing climate risk reduction for low-income and marginalized communities, including people living in informal settlements,” said Christopher Trisos, one of the report’s authors.
The report argues that there is enough global capital to rapidly reduce greenhouse gas emissions if existing barriers are lowered. “Increasing finance for climate investments is important to achieving global climate goals,” the press summary notes.
“Accelerated climate action will only be achieved if there is a multi-fold increase in funding. Insufficient and misaligned funding is holding back progress,” Trisos stresses.
Governments, through public funding and clear signals to investors, are key to lowering these barriers.
Investors, central banks and financial regulators can also play their part.
There are proven policy measures that can work to achieve deep emission reductions and build climate resilience if they are scaled up and applied more widely.
Political commitment, coordinated policies, international cooperation, ecosystem stewardship and inclusive governance are important for effective and equitable climate action.
If the right technology, know-how and policy measures are shared, and the right funding is now available, all communities can reduce or avoid carbon intensive consumption.
At the same time, “with significant investment in adaptation, we can avoid increasing risks, especially for vulnerable groups and regions.”
Effective and equitable conservation of approximately 30-50% of land and freshwater and oceans will help ensure a healthy planet.
Meanwhile, urban areas offer an opportunity on a global scale for ambitious climate action that contributes to sustainable development.
Changes in the food sector, electricity, transport, industry, buildings and land use can reduce greenhouse gas emissions.
At the same time, they can make it easier for people to lead low-carbon lifestyles, which will also improve health and well-being.
A better understanding of the consequences of binge drinking can help people make more informed decisions.
“Transformational changes are more likely to succeed where there is trust, where everyone works together to prioritize risk reduction, and where the benefits and burdens are shared fairly,” Lee said.
“We live in a diverse world where everyone has different responsibilities and different opportunities to create change. Some can do a lot, while others will need support to help them manage the change.”
