Is there any mistake in my five sentences?

Deforestation was the principal cause of (`cause for` means `a valid reason for`, while `cause of` means `this is the reason of it`) unproductive land in Europe, bringing (to avoid tautology: `cause`, `causing`) damage to 9.8% of land, compared with 1.7% in Oceania and 0.2% in North America. 

Deforestation was the principal cause of (I wouldn't use `the` here) unproductive land in Europe, causing damage to 9.8% of land, while the proportions of land degradation in the (I think `the` is necessary here, because you are contrasting two contries to Europe) other two countries were significantly lower.

Deforestation was the principal cause of (I wouldn't use `the` here) unproductive land in Europe, causing damage to 9.8% of land, while (I think, `while` is more appropriate than `but` here) the proportions of land degradation in the (I think `the` is necessary here, because you are contrasting two contries to Europe) other two countries were significantly lower.

Deforestation was the principal cause of (I wouldn't use `the` here) unproductive land in Europe, causing damage to 9.8% of land, while (As for me, `while`  is more appropriate than `but` here) the figures for the (I think `the` is necessary here, because you are contrasting two contries to Europe) other two countries were significantly lower.

Deforestation was the principal cause of (I wouldn't use `the` here) unproductive land in Europe, causing damage to 9.8% of land, while the figures for the (I think `the` is necessary here, because you are contrasting two contries to Europe) other two countries were significantly lower.

Is there any mistake in my five sentences?

Deforestation was the principal cause for unproductive land in Europe, causing damage to 9.8% of the land, compared to 1.7% in Oceania and 0.2% in North America respectively

Deforestation was the principal cause of __ unproductive land in Europe, causing damage to 9.8% of the land, while the proportions of land degradation in the other two countries were significantly lower.

Deforestation was the principal cause of __ unproductive land in Europe, causing damage to 9.8% of land, meanwhile the proportions of land degradation in the other two countries were significantly lower.

Deforestation was the principal cause of __ unproductive land in Europe, causing damage to 9.8% of land, while the figures for the other two countries were significantly lower.

Deforestation was the principal cause of the unproductive land in Europe, causing damage to 9.8% of the land, while the figures for the other two countries were significantly lower.

My comments:  a good structure. Just be sure that it's "cause of.." and put "while/meanwhile" instead of "but". Some further work with articles is required. All the rest is great!