Learn Danish: Opvarmningen af havet går hurtigere end ventet. - The warming of the sea is happening faster than expected.

In Danish, går is commonly used to describe the progress or speed of an ongoing process, much like asking 'how is it going?'. If you used sker (happens), it would focus on the mere fact that the event occurs, whereas går pairs perfectly with hurtigere to describe the pace of the process.

I thought 'expected' was forventet. Why does this sentence use ventet?

Both are correct here! You will often see hurtigere end forventet, but hurtigere end ventet is a very common fixed expression. While vente usually means 'to wait' and forvente means 'to expect', vente frequently takes on the meaning of 'expect' in formal or statistical contexts, especially when talking about forecasts or trends.

Could I write this using a compound noun, like havopvarmningen?

Absolutely. Havopvarmningen går hurtigere end ventet is perfectly natural. Writing it out as opvarmningen af havet just sounds slightly more formal or scientific, drawing distinct attention to the sea as the subject of the warming.

Why does the sentence end with just ventet without a subject or helping verb?

Just like in English, Danish often drops the subject and the 'to be' verb in comparative phrases to make them more concise. The full thought is end det var ventet (than it was expected), but the shortened phrase end ventet is the standard, natural way to express this.