seen before many parts of the world

[Maybo]

Now remember, this is happening when average world temperatures have only risen just over 1C beyond levels seen before many parts of the world became industrialised.
（UK heatwave: Why is it so hot? by Justin Rowlatt）

Is ‘which were’ omitted before ‘seen’?

 

[Barque]

Not a teacher

You've got the right idea. I'd say it's "that were" rather than "which were". I can't really explain why I prefer "that" to "which".

 

[Tarheel]

Now remember, this is happening when average world temperatures have only risen just over 1C beyond levels seen before many parts of the world became industrialised.
（UK heatwave: Why is it so hot? by Justin Rowlatt）

Is ‘which were’ omitted before ‘seen’?

Not in my opinion.

 

[Maybo]

Not in my opinion.

What is the sentence structure?

 

[Tarheel]

What is the sentence structure?

Well, it's a complex sentence (not a simple sentence).

These are not normally questions I field. (Jutfrank could answer this one easily.)

 

[Tdol]

Not a teacher

You've got the right idea. I'd say it's "that were" rather than "which were". I can't really explain why I prefer "that" to "which".

In British English you can use that/which were in a defining relative clause, but some variants prefer that.

 

[Maybo]

What were seen? Is it “average world temperatures”?

 

[jutfrank]

The levels of average world temperatures, yes.

 

[Maybo]

I found a sentence from the same article as follows:

They have helped push the concentration of carbon dioxide in the atmosphere to the highest levels seen for 2 million years, according to the IPCC.

What does “seen for 2 million years” mean?

 

[jutfrank]

The last time the concentration of carbon dioxide in the atmosphere was as high as it is now was two million years ago.

 

[Maybo]

They have helped push the concentration of carbon dioxide in the atmosphere to the highest levels seen for 2 million years, according to the IPCC.

Does the sentence mean the same if "seen" is removed? Because of "seen", I don't know how to parse the sentence correctly.

I've consulted the dictionary.
Does "seen" mean "happens" (to be the time or place when something happens)?

 

[jutfrank]

It means 'observed in the data'.

 

[Barque]

to the highest levels seen for 2 million years

You could read this as "to the highest levels that have been seen for two million years".

(I don't know how they know how much there was two million years ago but I suppose they have their methods.)

WouldDoes the sentence mean the same if "seen" is removed?

Yes, but it'd sound a little awkward in my opinion.
...to the highest levels for two million years.

You need something there along with "two million years".
...to the highest levels seen/observed for two million years.
...to the highest levels since two million years ago.
...to the highest levels there have been for two million years.

 

[5jj]

@Barque:
This is grammatical: Does the sentence mean the same if "seen" is removed?