Is climate change real?

Executive summary: The scientific literature and major science organizations state that global temperatures have risen and that human activities—chiefly greenhouse‑gas emissions—are the primary cause; that conclusion is summarized as a strong scientific consensus in multiple reviews and by bodies such as the IPCC ^{[1] [2]}. The exact headline percentage quoted varies across studies and commentators—figures cited in the provided sources include ranges from about 80–90% up to 97–99.9% depending on which population of scientists or papers is counted and how the question is framed ^{[3] [4] [5] [6]}.

1. Why scientists say “yes”: the consensus and its basis

Decades of research and syntheses—culminating in major assessment reports—conclude that global surface temperatures have increased in recent decades and that human‑induced greenhouse‑gas emissions are the dominant cause; the IPCC’s assessment and national science academies are invoked as the international consensus statement on this point ^{[1] [2]}. Reviews of the peer‑reviewed literature, meta‑analyses of surveys of experts, and statements from major scientific organizations all converge on the view that anthropogenic (human‑caused) warming is real ^{[7] [1]}.

2. Numbers matter: why different studies report different percentages

Different studies count different groups and use different methods, producing different headline percentages. Some surveys that focus on actively publishing climate scientists report very high agreement (commonly cited as ~97%) while broader surveys that include related Earth scientists or other specialties report lower percentages—often in the 80–90% range ^{[4] [3]}. Some recent papers and communications place consensus estimates even higher (97–99.9%), but these depend on definitions and selection of literature or respondents ^{[5] [6]}.

3. The methodological dispute behind “97%”

The popularly cited “97%” comes from specific analyses and surveys (for example, Cook et al. and surveys of active climate researchers) but has been critiqued on methodological grounds—principally that inclusions/exclusions and how categories are coded alter the result. Forbes’ fact‑check emphasizes that when specialties outside climate science are included, overall support falls below 97%, often to the 80–90% band ^[3]. Academic sources and databases show both the original Oreskes study and later work as key inputs to the broader consensus claim ^{[7] [3]}.

4. What consensus messaging does — and doesn’t — do

Large experimental studies across countries find that telling people about the scientific consensus increases their estimate of how many scientists agree, raises belief that climate change is human‑caused, and increases worry; however, it does not reliably convert that change into stronger support for public action in every context ^{[8] [9]}. The 27‑country test found consensus messaging effective and non‑polarizing for beliefs and worry but not consistently for policy support ^[8].

5. Where disagreement still exists — and why it matters

Scientists continue to debate the details: exact climate sensitivity, regional impacts, timing and magnitude of specific extremes, and optimal policy responses. The presence of high‑level consensus about human‑caused warming does not mean unanimity on every detail or on what policies to pursue; those technical and normative debates are active and shape recommendations ^[7]. Available sources do not mention a global scientific body rejecting the core finding that human activities are the main driver of recent warming ^[1].

6. Political and communicative dynamics that shape public perception

Public estimates of scientific agreement are much lower than many survey or literature‑based estimates: for example, a UK study reported public guesses around 65% agreement, far below some academic claims of >99% in selected literature ^[6]. Communication researchers warn that a gap between perceived and actual consensus can influence public opinion and policy support, and that tailored messaging matters across cultural and ideological contexts ^{[10] [11]}.

7. Bottom line for readers: what the evidence supports and limits

The body of peer‑reviewed science and major scientific organizations state unequivocally that recent warming is real and that human activity is the primary cause; exact consensus percentages vary with method and population sampled ^{[1] [7] [4]}. If your question is whether climate change is happening and substantially caused by humans, the available sources say yes; if your question is about the precise percentage of scientists who would endorse that statement under every survey design, the literature and commentary show legitimate variation and debate about the appropriate metric to use ^{[3] [12]}.

Limitations: this summary relies only on the provided sources; additional primary literature, policy reports, or further methodological critiques may add nuance not covered above.