If you already were worried about climate change, the latest news is even worse. Leading climatologist James Hanson published a significant paper on 3 February 2025 explaining why IPCC reports have underestimated the speed of global warming, which doubled from 0.2°C to 0.4°C annually in the last two years. New regulations on highly-polluting fuels used by shipping cut their pollution of pristine ocean air from 2020. That pollution created aerosols and denser clouds that reflected sunlight back into space, producing cooling that offset some global warming. With that cooling reduced, overall global warming accelerated. This showed that climate sensitivity to CO2 in the atmosphere is higher than previously assumed, not 3°C but 5°C for a doubling of CO2 concentration.
Hansen said: “The Intergovernmental Panel on Climate Change (IPPC) defined a scenario which gives a 50% chance to keep warming under 2°C – that scenario is now impossible. The 2°C target is dead, because the global energy use is rising, and it will continue to rise.” He adds that global temperatures are likely to reach 2°C by 2045. It is estimated that this will trigger a rise in sea levels by several meters, the melting of polar caps, and irreversible damage to critical ecosystems around the world.
On 2 February, the day before Hansen’s report, the North Pole experienced temperatures 30°C above average for that time of year, an unprecedented event that could have massive global consequences. This is not just about the ice melting, but impacts marine ecosystems and affects the entire global climate system. This extreme and sustained warming is not only unprecedented but also accelerating.
Climate impacts
The wide-ranging impacts of climate change have surprised even the scientific community, and are creating a humanitarian crisis. Between 2010 and 2020, 83 percent of all disasters caused by natural hazards were linked to climate extremes – especially floods, storms, droughts and extreme heat. Together these disasters affected 1.7 billion people, killing 410,000. In 2022, 70 percent of refugees and asylum seekers fled from highly climate-vulnerable countries. In 2023 climate extremes drove 72 million people into crisis or emergency levels of hunger and triggered over 20 million new internal displacements. Growing stress on water resources and shifting weather patterns are compounding people’s vulnerability in many hazard-prone locations.
Climate change is shifting the patterns of humanitarian crises as some hazards, such as extreme heat, become more common and others, such as tropical storms, intensify and behave less predictably. These shocks deepen social and economic inequality and reinforce social norms and structural barriers that already limit the capacity of women and girls, children and young people, persons with disabilities and other disproportionally affected groups to manage risk and adapt to changing conditions. It is projected that climate change could trigger the abrupt end of schooling for 12.5 million girls.
Food insecurity
Food insecurity and malnutrition are highest where the adverse impacts of climate change intersect with other drivers of hunger such as conflicts, structural poverty and economic inequality. In 2023, the 14 countries with the highest climate risk were also affected by conflict or fragility. This compound nature of many humanitarian crises makes it increasingly challenging to implement climate action and access climate financing in high-risk contexts.
The World Food Programme said climate shocks are making it increasingly difficult for families across Latin America and the Caribbean to produce, transport, and access food. Frequent storms and floods are destroying homes and farmland, while drought and erratic rainfall are wiping out crops before they can grow. As extreme weather makes healthier food options inaccessible, communities in climate-sensitive areas turn to cheaper, unhealthier food sources. In Latin America, the cost of a healthy diet is the highest in the world. As a result, child and adult obesity has risen significantly since 2000 in these areas. According to FAO’s studies, in the Caribbean approximately 50 percent of the population, or 22.2 million people, were unable to afford a healthy and balanced diet. In Mesoamerica, roughly 26.3 percent were unable to meet their nutrition needs. South America has the highest numbers, with 113.6 million people unable to afford proper nutrition. It has become increasingly apparent that sustainable agriculture practices and disaster risk management systems are crucial to fulfill growing needs as natural resources continue to dwindle.
With food systems accounting for 21–37 percent of anthropogenic greenhouse gas emissions, many countries are looking for coordinated international support and partnerships to de-carbonize and diversify food systems, increase the resilience and resource efficiency of value chains, and ensure that the food and nutrition needs of vulnerable communities can be met as the climate is changing.
Current climate targets accept large amounts of unrecognised natural and societal risk
Economic impacts
The Institute and Faculty of Actuaries (IFoA), in a January 2025 report, warns that the global economy could face a 50% loss in GDP between 2070 and 2090 unless immediate policy action is taken on risks posed by the climate crisis. Current climate targets accept large amounts of unrecognised natural and societal risk. This includes accepting triggering multiple tipping points where climate change thresholds, once crossed, may be irreversible and limit our ability to control climate change. Populations are already impacted by food system shocks, water insecurity, heat stress and infectious diseases. If unchecked, mass mortality, mass displacement, severe economic contraction and conflict become more likely. There is currently no realistic plan in place to avoid this scenario.
The Actuaries assessment of planetary solvency defines catastrophic impacts as:
- Economic contraction, GDP loss of over 25%.
- Mass human mortality events resulting in over 2 billion deaths.
- Warming of 2°C or more, triggering high number of climate tipping points.
- Breakdown of some critical ecosystem services and Earth Systems.
- Major Extinction Events in multiple geographies.
- Ocean circulation severely impacted.
- Severe socio-political fragmentation in many regions, low lying regions lost.
- Heat and water stress driving mass migration of billions.
- Catastrophic mortality events from disease, nutrition, thirst and conflict.
It will be overwhelmingly positive economically to avoid this, but our current market led approach to mitigating climate and nature risks is not delivering.
The actuaries policy recommendations include:
- Creating a responsibility for producing annual climate risk assessments, in the IMF or OECD, and reporting to the UN Security Council.
- Considering the need for systemic risk officers at supra-national, national and sub-national levels to enhance systemic risk management capability.
- Rapidly implementing policy recommendations to reduce risk such as national transition plans, nature positive pathways and alternative economic models.
- Developing appropriate tracking of delivery of solutions to mitigate risk, including oversight of progress, clear accountability and near-term action.
Time to act
It is clear from the latest science described above, the impact assessments, and the alarming economic risks of climate change, that we are on the edge of a precipice, and have perhaps already lost our balance. As scientists, we have been warning of this for decades, but vested interests and the powers that be have ignored us, if not trying to discredit us. Worse still, climate denial and concern for the environment have become top political issues among extremists in too many countries, and we are under attack. Fossil fuels are lauded as drivers of the economy and highly subsidised; renewable energy projects are prohibited. This can only accelerate the climate catastrophe already upon us. Refusal to take existential risks seriously does nothing to lessen their reality. The planet is shouting at us in its pain and suffering, but the longer we hesitate, the more disastrous will be the consequences. With this extreme failure of governance based on selfish national sovereignty, the urgency of effective global environmental governance is only reinforced. The time to act is now.
