[2026] PTE Academic Writing - Summarize written text

Ocean fertilization is a controversial geoengineering strategy that involves dispersing nutrients, such as iron or nitrogen, into the upper layers of the ocean to stimulate the growth of phytoplankton. Because phytoplankton utilize photosynthesis to absorb carbon dioxide from the atmosphere, increasing their population could theoretically accelerate the sequestration of greenhouse gases into the deep ocean. Proponents of this method argue that it offers a scalable and relatively low-cost solution for mitigating global warming on a massive scale.

However, the scientific community is deeply divided over the long-term ecological risks and the actual effectiveness of this approach. Large-scale algal blooms could inadvertently lead to 'dead zones' by depleting oxygen levels in the water, which would devastate local marine life and disrupt the delicate balance of the ocean food web. Furthermore, there is no guarantee that the captured carbon will remain sequestered in the deep sea rather than returning to the atmosphere through natural circulation. Due to these uncertainties, international treaties currently restrict large-scale ocean fertilization experiments until more robust data is available. As the climate crisis intensifies, the debate continues over whether the potential benefits of such intervention outweigh the risk of unforeseen catastrophic consequences for the planet's marine ecosystems.