The following sources can be very useful:
General: https://www.conserve-energy-future.com/top-25-environmental-concerns.php
Climate change: https://climate.nasa.gov/
https://en.wikipedia.org/wiki/Climate_change
Pollution: https://www.worldwildlife.org/threats/pollution
https://en.wikipedia.org/wiki/Pollution
Deforestation: https://www.nationalgeographic.com/environment/global-warming/deforestation/
https://www.worldwildlife.org/threats/deforestation-and-forest-degradation
https://en.wikipedia.org/wiki/Deforestation
Overpopulation: https://www.conserve-energy-future.com/causes-effects-solutions-of-overpopulation.php
https://en.wikipedia.org/wiki/Human_overpopulation
Excessive household and industrial waste: https://www.rootwell.com/blogs/worlds-garbage-problem
Acid Rain: https://www.nationalgeographic.com/environment/global-warming/acid-rain/
https://en.wikipedia.org/wiki/Acid_rain
Ozone Depletion: https://www.nationalgeographic.com/environment/global-warming/ozone-depletion/
https://en.wikipedia.org/wiki/Ozone_depletion
https://www.nasa.gov/feature/goddard/2018/nasa-study-first-direct-proof-of-ozone-hole-recovery-due-to-chemicals-ban
Urban Sprawl: https://www.conserve-energy-future.com/causes-and-effects-of-urban-sprawl.php
https://en.wikipedia.org/wiki/Urban_sprawl
https://greentumble.com/environmental-problems-of-urbanization/
Loss of biodiversity: https://wwf.panda.org/our_work/biodiversity/biodiversity_and_you/
https://www.britannica.com/science/biodiversity-loss
https://en.wikipedia.org/wiki/Biodiversity_loss
Outline of an argumentative text:
Before you start writing you argumentative text, you will need an outline of the text to know how you are going too structure your arguments. To learn how to make such an outline, click on the following link, https://writewellapp.com/example/argumentative-essay, or open the attachment at the bottom of this page. Follow the steps and create your outline for your text.
Example of an argumentative text on immigration: https://writewellapp.com/example/argumentative-essay-on-immigration
Other useful websites for academic writing in English:
Synonyms: https://www.thesaurus.com/browse/synonym
Dictionary: https://dictionary.cambridge.org/dictionary/
Linking words: https://web2.uvcs.uvic.ca/courses/elc/sample/ite/gs/gs_38.html