PREreview of The Impact of U.S. Withdrawal from the Paris Agreement on Global Climate Change Negotiations (Systematic Review)

Summary of the Research

This systematic review analyzes how the U.S. withdrawal from the Paris Agreement affected global climate negotiations, climate finance, and cooperation between developed and least developed countries. The author reviews political, scientific, and economic literature and argues that the withdrawal weakened climate finance commitments, disrupted diplomatic trust, and raised the risk of missing global warming targets. The paper also discusses implications for COP30 in Brazil and highlights how the absence of the U.S. creates leadership gaps, funding uncertainty, and reduced momentum in global climate governance.

Major Issues

1. The review presents many claims but does not consistently evaluate the strength of evidence

The paper synthesizes a large range of studies, but it does not critically compare how strong or weak the sources are. For example, claims about the decline in climate finance after U.S. withdrawal are stated clearly, but the paper does not show the size of the decline, the years affected, or how different reports measure it. A more systematic evaluation of the evidence would strengthen the conclusions.

2. The roles of developed and least developed countries are described broadly but not always supported by data

There is repeated mention that LDCs were most affected by the withdrawal, but the review does not include specific numbers or case examples. For instance, the paper says projects such as flood defenses and early warning systems were harmed, but it does not give examples of countries, funding losses, or measurable delays.

3. Some arguments are repeated throughout the paper without adding depth

Several statements appear multiple times, such as the idea that the withdrawal created a leadership vacuum, increased uncertainty, and encouraged other countries to weaken their commitments. These points are important, but they need more specific evidence, such as examples of negotiations that broke down or pledges that changed after the withdrawal.

4. Scientific implications rely on general statements rather than specific climate models

The paper references integrated assessment models and tipping point research but provides little detail. For example, it states that U.S. disengagement increases the likelihood of passing tipping points, but it does not show which model projections change or how much warming increases when U.S. emissions are excluded. More detail would increase credibility.

5. The methodology section describes the search strategy but lacks transparency in study selection

The review says it screened studies and resolved ambiguities but does not show how many studies were excluded, how many were kept, or what criteria determined final inclusion. Adding a flow chart or table summarizing the number of studies at each screening stage would make the review more rigorous.

6. The implications for COP30 are very broad and speculative

The paper presents many expectations for Brazil’s role and for future negotiations but does not explain how these ideas are supported by existing literature. For example, suggestions that Brazil can bridge diplomatic divides are not linked to any past evidence. Some statements read more like policy recommendations rather than findings based on the reviewed studies.

Minor Issues

1. The introduction repeats points about U.S. political instability

The introduction states multiple times that U.S. domestic politics undermine climate leadership. These ideas could be condensed into one strong paragraph.

2. The paper sometimes shifts tone from academic to conversational

Phrases such as “pretty important” or “it makes it much harder” do not match the otherwise formal writing style.

3. Some figures are referenced but not explained clearly

For example, Figure 1 is said to summarize key implications but is not described with enough detail for readers to understand it without viewing the graphic.

4. Some sections mix scientific, political, and economic arguments

The scientific discussion includes governance topics, while economic discussion includes scientific statements. Separating these topics more clearly would improve organization.

5. Several statements appear to duplicate earlier lines

For instance, the discussion of the U.S. accounting for around 15 percent of global emissions appears almost word for word more than once. Editing for repetition would help streamline the text.

Competing interests

The author declares that they have no competing interests.

Use of Artificial Intelligence (AI)

The author declares that they did not use generative AI to come up with new ideas for their review.