The fundamental mechanism of climate change has been understood for over a century, built on rigorous scientific work and continuous validation. In the 1850s, John Tyndall demonstrated how gases trap heat in the atmosphere. Svante Arrhenius later quantified how carbon dioxide changes could alter Earth's temperature (1896), while Guy Callendar connected rising CO2 levels to observed warming (1938).

This theoretical foundation has been repeatedly confirmed through direct observations, particularly from the Mauna Loa Observatory's continuous CO2 measurements since 1958 and comprehensive satellite monitoring programs. The basic physics of how greenhouse gases trap heat and influence global temperature is as well-established as our understanding of gravity or cellular biology.

Areas of ongoing scientific investigation

While the basic mechanisms of climate change are well understood and supported by extensive evidence, there are several areas where scientific investigation continues to expand our knowledge and understanding. These areas of ongoing research don't challenge the fundamental physics of greenhouse gas warming, but rather explore the complexities of how this warming affects Earth's interconnected systems and what it means for our future. Each area presents unique challenges for scientists and helps explain why public climate change discussions often involve debates about uncertainty.

Attribution Science

While we can confidently link global warming to human activities, determining the exact contribution of climate change to specific weather events is more complex. Attribution science uses sophisticated statistical methods and modelling to estimate how much more likely or severe an event became due to climate change. For example, while we cannot say climate change "caused" a specific hurricane, we can calculate how much more likely such intense storms have become in our warmer world.

The Pakistan floods in 2002 were found to be made 50% more intense by climate change. While more recently the frequency of storms such as Hurricane Helene hitting the Gulf of Mexico in 2024 was found to have increased by 150% because of climate change.

Spatial variability

Climate impacts vary significantly across different regions. While global average temperature changes are well understood, predicting local effects presents greater challenges. Some areas may experience more dramatic warming, others more extreme rainfall or drought. Understanding these regional variations requires complex modelling of atmospheric and oceanic circulation patterns, which contain inherent uncertainties.

While the global average temperature has increased by approximately 1.1°C since pre-industrial times, the Arctic has warmed nearly four times faster, with some areas like the Barents Sea warming up to seven times faster than the global average. In contrast, parts of the Southern Ocean around Antarctica have warmed much more slowly or even slightly cooled.

Human behaviour in climate models

Perhaps the greatest uncertainty in climate projections comes from predicting human actions. Future emissions depend on population growth, technological development, economic policies, and societal choices. Climate models use different scenarios (called Representative Concentration Pathways) to account for various possible futures, each with different levels of emissions reduction.

Current scenarios range from SSP1-1.9 (aggressive emissions reduction leading to 1.5°C warming) to SSP5-8.5 (continued high emissions leading to 4-5°C warming). The difference between these pathways could mean as much as 4 metres of sea level rise by 2300, demonstrating how human choices today can drastically affect future outcomes.

Solution pathways and consequences

While many climate solutions are well-understood (renewable energy, energy efficiency, reforestation), their full implications can be complex. For instance, large-scale bioenergy production might compete with food production, or mineral extraction for batteries might impact ecosystems. Understanding these trade-offs and potential unintended consequences requires ongoing research and careful analysis.

For example, studies in Southeast Asia have shown how poorly planned biofuel production can lead to deforestation, potentially creating more emissions than it saves.

Impact prediction

Predicting specific impacts of climate change involves complex interactions between physical, biological, and social systems. While we can confidently predict general trends (sea-level rise, increased heat waves), quantifying precise impacts on agriculture, biodiversity, or human health involves greater uncertainty, particularly at local scales.

While we can project that wheat yields will decline with rising temperatures, the exact impact varies greatly by region. Studies suggest yields could drop by 4-6% for each degree of warming globally, but some regions might actually see initial increases before declining.

Climate tipping points

Some elements of the Earth system may have critical thresholds beyond which rapid and potentially irreversible changes occur. Examples include the collapse of ice sheets or changes in ocean circulation patterns. While we understand these possibilities exist, precisely predicting when such tipping points might be reached remains challenging.

Current research identifies several potential tipping points: the Greenland ice sheet could become unstable at 1.5°C of warming, while the West Antarctic ice sheet faces similar risks at 2°C.