Can you check grammar error in this text?

What can you do to reduce global warming in Thailand?
Nowadays, The problem global warming is main problem for everybody in the world. It is effect on change of weather that the world have temperature highest. In Thailand, the problem global warming affect to Thai people such as flood. So we should reduce global warming in Thailand with these easy step.
The first step, we should save electric energy such as turn of light, turn off television or turn off computer when you go out the home. The second step is to use measure 3Rs is reduce, reuse and recycle according to plan of government. The third step, we should to help plant the trees around our house. The forth step is to use cotton bag instead of plastic bag or use basket instead of plastic bag when you bought vegetables and shopping. The last step, we should to use bicycle instead of a car because it can save gasoline and you yet also exercise.
All together it is step can help reduce global warming in Thailand that you can make it. To sum up, we can help reduce global warming following these easy step and you should to use energy when you need.

First, if you are learning English as a second language, you seem to be doing very well so far. But there are many errors in this essay.

First, "Nowadays, the problem OF global warming..." No capital letters in the middle of a sentence unless it's a proper noun.

"...is main problem..." Is it? Does everybody in the world identify it as the main problem? You might better say, "...is A MAJOR problem..."

The next sentence, "It is effect on weather..." doesn't make sense. Try: "One effect of global warming is that temperatures around the world are the highest on record. Another effect on Thailand is that global warming causes increased flooding." But, you do not explain how increased flooding is due to global warming. You should do that.

In many places your subject and verb or noun and pronoun do not agree. It should be "...these easy stepS.." These is plural, so step should also be plural.

"we should turn off our televisions, lights, and computers when we leave the home to save electricity." Or: "We should save electric energy BY TURNING OFF..." "By" is a proposition, so by must be followed by a noun or noun phrase. Using the gerund "turning" does that, etc.

"...3Rs: reduce, reuse, and recycle according to..." Here, the colon is useful to introduce the list. And, in a series like this, use a comma after each, including before the "and."

"...plan of government." is awkward. You might write, "...according to our government's plan."

Go through the rest of your essay for similar errors.

Look for things like when you use a cotton bag or basket, "bought" is past tense, but the rest of the sentence is not. Write "when buying vegetables or shopping." Make it all agree.

Good luck!

Sure! Here is the corrected version of your text with the grammar errors fixed:

What can you do to reduce global warming in Thailand?
Nowadays, the problem of global warming is a major concern for everybody in the world. It affects the change in weather and leads to higher temperatures worldwide. In Thailand, global warming has a significant impact on Thai people, such as floods. Therefore, we should take steps to reduce global warming in Thailand with these easy steps.

The first step is to save electric energy, such as turning off lights, television, or computers when leaving home. The second step is to adopt the measures of the 3Rs: reduce, reuse, and recycle, following the government's plan. The third step is to plant trees around our houses. The fourth step is to use cotton bags instead of plastic bags or baskets when buying vegetables and other shopping items. Finally, using a bicycle instead of a car can not only save gasoline but also provide exercise.

All together, these steps can help reduce global warming in Thailand, and you can implement them easily. In conclusion, by following these simple steps and using energy only when necessary, we can contribute to the reduction of global warming.