It is argued by some that making car fuel more expensive [IS] the most viable measure to take to combat environmental issues

Task 2
It is argued by some that making car fuel more expensive [IS] the most viable measure to take to combat environmental issues. Even though this method could work to a certain extent, I believe reducing the number of cars on roads through this measure alone is not likely to remedy our current environmental predicament.
On the one hand, exhaust fumes from cars make up merely a minor proportion of all damage caused to the nature. In other words, such environmental issues as global warming and soil and water contamination result largely from mass-scale deforestation practices and chemical spills from chemical plants, and the contribution of emissions from petrol-driven vehicles is rather minimal in comparison. Therefore, efforts to discourage the public from driving by making this activity more costly would solve only a part of this complex problem. I believe, the most workable solution to tackle our modern-day environmental problems would be employing an [A] complex method to fight against all forms of environmentally damaging activities by imposing new forms of [+SMTH IS MISSING] on businesses responsible for land clearance and carbon monoxide emissions, and individuals who own more than a single private vehicle.
On the other hand, artificially inflating petrol prices might indeed bring about certain desirable results in the fight against issues with the nature. Firstly, it is common knowledge that old cars release larger amounts of fumes because of their old-fashioned engines, so higher fuel prices could discourse [I think you meant DISCOURAGE here] the owners of such vehicles from driving altogether considering that most of these outdated cars are owned by the lower class. Secondly, increased driving expenses might potentially speed up the introduction of electric vehicles which [?] and generally lower the gross exhaust fumes from cars. This being said, however, petrol-powered cars are not the sole contributors to the environmental degradation we are facing now, and solving this issue with cars would only partially solve the problem.
In conclusion, even though raising fuel prices would indeed solve some part of the problem, I do not agree that this would be the best way to solve our complex environmental issues as the other ways in which our nature is ruined cannot be overlooked.
I liked the conclusion.

Overall, it is a high-level essay. However, the way I organize my paragraphs for this essay would be different though. I would firstly say that it is an effective measure like you did, and after that would talk about alternative or complementary solutions of dealing with green issues. In your thesis, you mentioned that it could work to a certain extent in the first clause, but discussed it in the second body. I do not think that it is a serious problem though. I also have a feeling that band 8.0+ essays should be impeccable, so you should set aside some time to edit and polish your work; I guess you did it, but a few mistakes were spotted, although the majority of your sentences were error-free.

TR: 8.0
CC: 7.0 (most sentences start with a linking device, and this may drag the CC score down to 7.0 (over-use of linking words))
LR: 8.0
GRA: 8.0
By the way, unless a candidate fulfills each requirement of an individual criterion, examiners move down by a band.

Task 1
The table provides the statistics regarding the various genres of movies produced in the UK and Republic of Ireland in the year 2012.

Overall, biopic films had by far the highest revenue to film ratio while the documentary was the least profitable genre. It is also clear that the comedy movies brought in the highest income among all other genres.
the highest revenue to film ratio  revenue to film NUMBER ratio maybe?
I would also include information about the highest number of films and their proportions.
Interestingly, even though only 1 release of biopic genre was produced it accounted for 9.1% of the gross income from selling tickets as opposed to only 2.9% and 8.3% of the total revenue generated by 35 documentaries and the same number of dramas respectively. Both crime and action films were relatively less popular genres among the film producers even though they made 4.7 % and 4.1% of the total income which were still much higher than most other mainstream genres such as thrillers.
A total of 26 comedies were shot in 2012 alone and they altogether constituted a whopping 45.4% of the total film revenue in this year. This was closely followed by horror movies which , with [punctuation error here] only 14 releases, were responsible for slightly more than a fifth of the gross income of the film industry in 2012.

I would personally group my data differently. I would firstly write about the number of releases and their percentage, and then talk about the percentage of income from ticket sales. In my opinion, the paragraphing would be more sufficiently used this way.

TA: 7.0 (presents and highlights key features, but they could be more fully extended)
CC: 7.0 (paragraphing)
LR: 8.0
GRA: 8.0