Slightly confusingly worded, but in any case;
Are you looking to study engineering in the UK, or elsewhere? This site mainly caters to UK students/universities, although there are some who have knowledge of international admissions/study as well.
Within the UK, A-level Maths (or equivalent, e.g. IB HL) is a virtually ubiquitous requirement for any engineering course in the UK. The vast majority also expect A-level Physics. Some however accept A-level Chemistry in lieu of A-level Physics (mainly chemical/materials engineering, sometimes biological engineering related courses as well). A few accept any science along with A-level Maths, but these are in the minority. A handful require A-level Maths and Physics with a third science subject, which is normally Chemistry but a handful of biomedical engineering courses expect A-level Biology. A-level Further Maths, while rarely, if ever, formally required is usually highly recommended and considered very useful.
As such the requirements vary, but generally taking A-level Maths and Physics will meet the criteria you for most courses, and taking A-level Chemistry and/or Further Maths is useful or sometimes required background. However many apply with just A-level Maths and Physics on the STEM side and take e.g. A-level Economics, History, Art, or any other number of subjects as a third. This may be less competitive for the "top" universities here however.
A-level Maths, Further Maths, Physics, and Chemistry is not an uncommon combination of four, and unlike most combinations of four A-levels is a relevant and useful combination and due to cumulative/overlapping content in maths/FM/physics, is not an impossible amount of work (although obviously more than just taking three). However Physics/Maths/FM or Physics/Maths/Chemistry are perfectly suitably if you are only able or willing to take three A-levels.
International requirements are likely to vary, and you should check individual universities' requirements before applying (if it's unclear, contact them directly, and they should be happy to advise). However in general, engineering in any discipline is primarily maths and physics, so taking as much maths especially, and to a lesser extent physics or perhaps other sciences, would be useful preparation even if not formally required.
Environmental engineering is generally a sub-discipline of civil engineering, but energy aspects relating to global climate change may be approached from a variety of different engineering disciplines (such as electrical/electronic, chemical, materials, mechanical, civil...virtually any discipline except biomedical engineering would be directly relevant in some way, and even that might be relevant in a less direct way in terms of basic engineering sciences).