"Therefore a curse consumes the earth; its people must bear their guilt. Therefore earth's inhabitants are burned up, and very few are left." NIV translation
The Hebrew word for curse is alah and it speaks of the judgment of God and the taking of something. In this case, it is referring to the taking away of God's hand of provision and sustenance for the world.
The fact that this was brought about by the people that remain on the earth is made clear with the Hebrew word "asham" which is translated as "bear their guilt". When you reject Jesus as the Lord, then, God is under no obligation to continue to provide for your needs.
Because of God's withdrawing His hand of provision, this will be a time of famine, plague, and strife. This is what John saw with the opening of the seven seals in the Book of Revelation (see Revelation 6).
The Hebrew word for burned up is charar and it literally speaks of burning or melting but also of drying up. This is what Isaiah is talking about here as the short supply of water and food will cause people to physically dry up. Most of us have seen pictures of starving and thirsty people and would describe them as shriveling up.
Many people will die from this while others are killed in the struggle to control what little food and water is left. As we see in John's revelation, one fourth of the earth's people will die from this part of the judgment.
"The new wine dries up and the vine withers; all the merrymakers groan. The joyful timbrels are stilled, the noise of the revelers has stopped, the joyful harp is silent. No longer do they drink wine with a song; the beer is bitter to its drinkers." NIV translation
This will be a time of great sorrow and the days of "wine, women, and song" are over. There will no longer be parties and singing as every waking hour will be spent just trying to get enough food and drink to survive. Even those that have will not be able to enjoy it as they will know that even their supply is running out.