Are you here to figure how to answer climate denialists when they say "bro, if global warming really exists, why are we having colder winters?"
Well, long story short - the answer is El Nino & La Nina.
The entire system is quite complex, but we're here to break it down for you. For more details, you're going to have to look it up, but this will be enough to tell the climate denialists to STFU.
So, we've got the Pacific ocean.
The Pacific ocean has an East and a West.
Usually, you've got trade winds that blow from East Pacific to the West Pacific along the equator. These trade winds carry heat & moisture from the East Pacific ocean to the West Pacific Ocean. This is perfectly normal. This is in a neutral state.
Now, you've got ENSO. ENSO is the term given to a recurring weather pattern. It includes El Nino, neutral, and La Nina - they are different phases of ENSO.
Now, during an El Nino phase, the trade winds weaken. As a result, they don't carry heat all the way to the western Pacific ocean. So when the heat isn't being taken to the West, the East and the Centre of the Pacific ocean begin to warm instead.
So you've got colder ocean temperature in the West, and warmer ocean temperature in the East. Countries located toward the western side will experience droughts. Why? Remember how we said trade winds also carry moisture?
Trade winds are necessary for bringing rainfall to a region. If your trade winds are weak, your rainfall will be too.
La Nina is the opposite of El Nino.
During a La Nina event, trade winds get stronger.
As mentioned before, trade winds carry warmth & moisture from the east to the west of the Pacific. So, if you've got stronger trade winds, then it means that more warm water will move from the east to the west which will cause western pacific ocean temperatures to rise.
The west here will face the onslaught of trade winds, which like we said before, carry moisture.
More moisture & harsher winds = More rainfall & harsher winters.
Now, El Nino and La Nina are natural phenomena. The state of the ocean currents oscillates between El Nino, neutral, and La Nina.
The real question isn't - “Will global warming cause El Nino and La Nina?”
The real question is, what will be the effect of global warming on El Nino and La Nina?
Global warming WILL change the intensity, frequency, and strength of such weather events.
Will this lead to droughts, rainfall disturbances, famine, and harsh weather?
So the next time someone says, "why are we having cold winters if global warming exists?"
Well, be sure to tell them, "it ain't that simple, buddy."