Humans are an intellectual beings.

First off, I would like to provide a wider range of definitions of intelligence that you have provided; yes, intelligent beings are often described as needing to be able to solve problems head on, but it is far larger than that. Intelligence can be described as (per dictionary.com) the "capacity for learning, reasoning, understanding, and similar forms of mental activity; aptitude in grasping truths, relationships, facts, meanings, ect.". Whilst the ability to solve problems comes under some of the definitions provided, it also entails communication, speech, self-awareness and the ability to learn. But with that said, onto the rebuttals; 1. They cannot solve problems like warfare - Often times, problems such as conflict and warfare cannot be sorted out by simple communication and diplomacy, as much as we would want. Warfare comes about by a number of reasons, often long standing tensions, such as what happened in both of the World Wars. The failure to make peace with the perceived enemy often chalks up, not our disability to make intellectual peace, but to make emotional war. Humans are animals, and like a number of animals, not only do our brain make rational decisions, but our emotions make irrational decisions. Emotions are the feeling often dissociated with rational, intelligent thoughts, and the way we evolved, as animals, often dictates that we should use emotion, not intelligence, as our prime mover, despite the fact that the intelligence is still there. Think about times during which warfare could of perceivably broken out (the Cuban Missile Crisis, the Berlin Blockade, ect.), and think of the damage that could of been done. Even in times of heightened emotion, humans can pull together, and use what they learnt, discern the facts, and come to a completely rational, intelligent compromise. 2. Our inability to explore space - This argument essentially fails to realize that space exploration is incredibly expensive and dangerous. Our ability to advance so far is an achievement within itself, but our lack of knowledge about said exploration is lacking. This, however, doesn't mean we're not intelligent, for as I stated before, intelligence is also the ability to learn, and that is what we have been able to do; learn from previous mistakes and build on them. Our scientific achievements, whilst obscured by governments in the past (the European dark ages for instance) chalks down more to human corruption (emotion) than it does to our lack of intelligence. Besides, would you be saying that we aren't intelligent if, in the future, we made advanced spaceships and planetary colonisers; scientific advance just takes time. 3. Humans destroying nature - I would like to say, before the modern age (1800 to now), the popular conciousness didn't know of global warming, or the far reaching effects of pollution; but as I've said before, lack of knowledge doesn't equal lack of intelligence. Today, thousands of people are protesting against large scale pollution caused by corporations, but our failure to do anything comes down to emotional corruption, caused by the greed of people and corporations (but let's not get into that). As I have already stated, emotions, and the ability to control them, would not make us any more intelligent than we could presently be, and would, in theory, make us less human (but again, let's not get into that). Governments around the world, together, right now, are bonding together to fight back against carbon emissions and global warming. This togetherness, this ability to (attempt) to solve problems, is something that is said to be defining attribute for intelligence, and our disability to completely solve it today can be chalked up to our complete misunderstanding and lack of foreknowledge in the past. 4. Medical advances - This could possibly be rebutted with the same arguments put out by the "space exploration" rebuttal, but contains language that needs to be looked into. As I stated before, our lack of scientific advance in the past doesn't mean we are any less intelligent, and the fact that today we are advancing more quickly than ever before is a testament to our intelligence, not a detriment. The fact that you bring up human cloning is an interesting point, and is more of a moral debate, especially after stating they would be used for harvesting internal organs; something of which is going to be completely unnecessary in a few years, due to the advent of 3D printing, and the advances into the bio-engineering of internal organs. Conclusion - Humans, no matter how emotional we get, no matter how much knowledge we lack, we still are intelligent beings, especially today, with the advent of technologies and innovations in all field of life that were not thought possible 10 years ago. Our progress today is a testament to our intellect, with the ability to cure many diseases, solve problems peacefully through international co-operation, and our opening advances into a new age of space exploration is truly a mark of our true intelligence.