By 2050 there will have been an extra 2.5 billion people on earth. And what will they eat? To solve the problem, we should have to double our food production. We can also develop a diet of algae , insects and meat grown in laboratories. Algae can grow very quickly at sea, in polluted water and in places that would normally kill food crops. They are already eaten widely in Japan and China and they are eaten by almost everything from shrimps to blue whales. They can fix CO2 in the atmosphere and provide fats and sugars. Man-made meat looks like meat, feels like meat and it is meat, although it's never been from a living, breathing animal. Instead, it is grown from cells in big containers. Moreover, studies show that producing man-made meat will use far less water, energy and land. China has developed "green super rice", a series of rice types which produce more grain and have stronger ability to fight against floods, salty water, insects and disease. We used traditional plant breeding techniques to cross-breed more than 250 rice types. Green super rice, which is enough to feed an extra 100 million people, will be planted widely in the coming years. Insects like ants are not on most European menus but at least 1,400 kinds are eaten across Africa, Latin America and Asia. Now, with rising food prices and worldwide land shortages, such insects are getting more and more popular. Not only are many insects rich in protein , low in fat and high in Ca and Fe, but insect farms need little space. And they can grow well on paper, algae and industrial wastes. In order to exist in the future, people have to   _  .
move to other planets produce rain in laboratories build new laboratories for food research increase the food production or look for other food sources