IELTS Reading: Climate Change

Paragraph A The Earth's climate has always been subject to natural variation, yet the scale and velocity of warming observed since the mid-twentieth century represent a departure from any precedent within recorded geological history. The Intergovernmental Panel on Climate Change (IPCC) reported in its 2021 assessment that global mean surface temperatures have risen by approximately 1.1 degrees Celsius above pre-industrial levels, a figure driven overwhelmingly by the accumulation of greenhouse gases in the atmosphere. Carbon dioxide, released through the combustion of fossil fuels and large-scale deforestation, now exists in concentrations exceeding 420 parts per million — a threshold not reached in at least three million years. Scientists working across disciplines have reached a near-unanimous consensus that without substantial reductions in anthropogenic emissions, warming of 1.5 to 2 degrees Celsius above baseline levels will be achieved well before the century's end, carrying consequences of profound and potentially irreversible magnitude.

Paragraph B The relationship between carbon emissions and atmospheric warming is mediated by what climate scientists term the greenhouse effect. Solar radiation penetrates the atmosphere and heats the Earth's surface; that heat is then re-emitted as infrared radiation, a portion of which is absorbed by greenhouse gases rather than escaping into space. Water vapour, methane, and nitrous oxide all contribute to this mechanism, yet carbon dioxide is considered the primary driver of long-term warming owing to its persistence in the atmosphere — molecules of CO₂ may remain active for centuries. A study published in the journal Nature Climate Change by Ramírez et al. (2019) found that the top twenty fossil-fuel-producing corporations accounted for roughly 35 percent of global industrial greenhouse gas emissions since 1965, underscoring how heavily concentrated the sources of the problem remain despite widespread public awareness of its existence.

Paragraph C Among the most visibly alarming consequences of sustained global warming is the acceleration of sea-level rise. Thermal expansion of ocean water accounts for roughly half of the observed increase, while the remainder is attributed to the melting of glaciers and polar ice sheets. Between 1993 and 2023, global mean sea levels rose by approximately 10 centimetres, yet projections suggest this rate is itself accelerating. Research conducted by the Potsdam Institute for Climate Impact Research indicates that, under a high-emissions scenario, sea levels could rise by as much as one metre by 2100, placing an estimated 200 million people in low-lying coastal zones at severe risk of flooding. Small island nations in the Pacific and Indian Oceans face existential threats, with some projections indicating that entire inhabited territories may become uninhabitable within decades, not centuries.

Paragraph D The international community's response to the climate crisis has been characterised by a persistent tension between ambition and implementation. The Paris Agreement of 2015, ratified by 196 parties, established the landmark goal of limiting global warming to 1.5 degrees Celsius, with a ceiling of 2 degrees, relative to pre-industrial levels. However, independent analyses by organisations such as Climate Action Tracker have consistently found that the nationally determined contributions submitted by signatory states are collectively insufficient to achieve even the more modest 2-degree target. Critics argue that the agreement's voluntary, non-binding architecture, while diplomatically necessary, fundamentally undermines its capacity to compel the emissions reductions required. Proponents counter that the framework creates normative pressure and provides a platform for ratcheting up ambitions over successive review cycles.

Paragraph E Economic considerations have long complicated the adoption of more stringent climate policy. Carbon pricing mechanisms — whether in the form of direct taxes or cap-and-trade schemes — are widely regarded by economists as among the most efficient tools for reducing emissions, as they internalise the social cost of carbon into market decisions. Nevertheless, such instruments remain politically contentious. A 2022 report by the World Bank found that only 23 percent of global greenhouse gas emissions were covered by any form of carbon pricing, and that the average price of carbon across existing schemes remained far below the level economists deem necessary to drive transformative change. The fossil fuel industry continues to receive substantial state subsidies in many jurisdictions, a reality that many researchers argue actively counteracts climate mitigation efforts.

Paragraph F There is growing scholarly debate about whether incremental policy adjustments will prove adequate or whether more systemic economic transformation is required. Some researchers, including Professor Yvonne Hartwell of the London School of Economics, contend that decarbonisation at the necessary scale demands not merely the substitution of renewable energy for fossil fuels, but a fundamental rethinking of consumption-led growth models. Others maintain that technological innovation — particularly advances in carbon capture and storage and next-generation nuclear energy — may yet provide viable pathways to net-zero emissions without requiring such structural upheaval. What appears certain is that the window for achieving the targets set under international agreements is narrowing rapidly, and that the decisions made by governments and industries over the next decade will have consequences extending far beyond the present generation.