When did global warming start
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The Onset of Global Warming: A Historical Perspective
Early Scientific Predictions and Skepticism
The concept of global warming was first introduced in 1896 when a physical chemist predicted that doubling atmospheric carbon dioxide levels would significantly increase global temperatures3. Despite this early prediction, the scientific community initially met the theory with skepticism. It took decades of accumulating evidence to convince experts of the reality of human-induced global warming3.
Industrial-Era Warming: Mid-19th Century Onset
Sustained industrial-era warming began in the mid-19th century, coinciding with the rise of industrial activities that increased greenhouse gas emissions. This period marked the first significant and sustained warming of the tropical oceans and Northern Hemisphere continents2. The early onset of this warming suggests that human activities started influencing the climate much earlier than previously thought, with greenhouse gas emissions playing a crucial role2.
Early 20th Century Warming
The early 20th century experienced a notable warming phase, particularly from 1925 to 1944. This period, known as the Early Twentieth Century Warming (ETCW), saw significant temperature increases attributed to a combination of natural variability and human-induced radiative forcing4 6. Although the exact causes remain complex, it is clear that both natural and anthropogenic factors contributed to this warming phase4 6.
Post-1970s Acceleration
Global warming became evident beyond natural variability in the 1970s, with a marked increase in global mean surface temperatures1. This period saw a more pronounced warming trend, largely driven by the continued rise in atmospheric greenhouse gases, particularly carbon dioxide1. The warming trend has persisted, albeit with fluctuations due to natural variations such as volcanic eruptions and changes in solar radiation1.
Long-Term Anthropogenic Influence
Some researchers argue that human influence on the climate began thousands of years ago, with early agricultural practices contributing to increased atmospheric concentrations of CO2 and CH47. This hypothesis suggests that anthropogenic emissions have been altering the climate for much longer than the industrial era, with significant impacts on global temperatures and even preventing a glaciation event in northeastern Canada7.
Conclusion
The onset of global warming can be traced back to multiple points in history, from early scientific predictions in the late 19th century to the mid-19th century industrial-era warming and the more pronounced warming trends observed since the 1970s. While natural variability has played a role, the evidence overwhelmingly points to human activities as the primary driver of the sustained and accelerating global temperature increases. Understanding this historical context is crucial for addressing the ongoing and future impacts of climate change.
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An apparent hiatus in global warming?
Global warming has not stopped; it is merely manifested in different ways, with sea-level rise being more relentless.
Highly CitedEarly onset of industrial-era warming across the oceans and continents
Industrial-era warming began in the mid-19th century, with tropical oceans warming first and Northern Hemisphere warming nearly synchronously.
Rigorous JournalHighly CitedGlobal warming: How skepticism became denial
The public's denial of global warming stems from a professional public relations effort driven by industrial and ideological concerns, and scientists need to mount a concerted public relations campaign to restore trust.
The early 20th century warming: Anomalies, causes, and consequences
The Early Twentieth Century Warming (ETCW) was driven by a combination of greenhouse gases and natural forcing, with aerosols playing a minor role, and included exceptional events like the Dust Bowl droughts and European droughts.
Literature ReviewHighly CitedKick-starting ancient warming
A catastrophic release of greenhouse gases from the Kilda basin could have triggered ancient warming, causing rapid global warming between the Palaeocene and Eocene periods 55.6 million years ago.
Simulation of early 20th century global warming
Early 20th century global warming may have been caused by a combination of human-induced radiative forcing and unusually large internal ocean-atmosphere variability.
Highly CitedThe Anthropogenic Greenhouse Era Began Thousands of Years Ago
The anthropogenic greenhouse era began thousands of years ago, with early agriculture in Eurasia contributing to global warming and forest regrowth during the Little Ice Age.
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The global land surface air temperature trend shows a notable warming trend since 1900, with the fastest warming in northern mid-latitudes and subtropical and subpolar regions of the Northern Hemisphere.
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