pug(旧jade)がインストールできない

###前提・実現したいこと
pug(旧jade)をインストールしようとしたら以下のようなエラーが出ました。
どのようにすればインストールできますでしょうか
node.jsはインストール済みです

###発生している問題・エラーメッセージ

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KobayashiKentaro-no-MacBook-Pro:~ kobayashikentaro$ npm i pug-cli -g
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
/usr/local/lib
└─┬ pug-cli@1.0.0-alpha6
├─┬ chalk@1.1.3
│ ├── ansi-styles@2.2.1
│ ├── escape-string-regexp@1.0.5
│ ├─┬ has-ansi@2.0.0
│ │ └── ansi-regex@2.1.1
│ ├── strip-ansi@3.0.1
│ └── supports-color@2.0.0
├─┬ commander@2.9.0
│ └── graceful-readlink@1.0.1
├─┬ mkdirp@0.5.1
│ └── minimist@0.0.8
└─┬ pug@2.0.0-beta.12
├─┬ pug-code-gen@1.1.1
│ ├─┬ constantinople@3.1.0
│ │ ├── acorn@3.3.0
│ │ └── is-expression@2.1.0
│ ├── doctypes@1.1.0
│ ├── js-stringify@1.0.2
│ ├── pug-attrs@2.0.2
│ ├── pug-error@1.3.2
│ ├── void-elements@2.0.1
│ └─┬ with@5.1.1
│ └─┬ acorn-globals@3.1.0
│ └── acorn@4.0.11
├─┬ pug-filters@2.1.2
│ ├─┬ clean-css@3.4.25
│ │ ├── commander@2.8.1
│ │ └─┬ source-map@0.4.4
│ │ └── amdefine@1.0.1
│ ├─┬ jstransformer@1.0.0
│ │ ├── is-promise@2.1.0
│ │ └─┬ promise@7.1.1
│ │ └── asap@2.0.5
│ ├── pug-walk@1.1.2
│ ├─┬ resolve@1.3.3
│ │ └── path-parse@1.0.5
│ └─┬ uglify-js@2.8.22
│ ├── source-map@0.5.6
│ ├── uglify-to-browserify@1.0.2
│ └─┬ yargs@3.10.0
│ ├── camelcase@1.2.1
│ ├─┬ cliui@2.1.0
│ │ ├─┬ center-align@0.1.3
│ │ │ ├─┬ align-text@0.1.4
│ │ │ │ ├─┬ kind-of@3.2.0
│ │ │ │ │ └── is-buffer@1.1.5
│ │ │ │ ├── longest@1.0.1
│ │ │ │ └── repeat-string@1.6.1
│ │ │ └── lazy-cache@1.0.4
│ │ ├── right-align@0.1.3
│ │ └── wordwrap@0.0.2
│ ├── decamelize@1.2.0
│ └── window-size@0.1.0
├─┬ pug-lexer@3.1.0
│ ├─┬ character-parser@2.2.0
│ │ └─┬ is-regex@1.0.4
│ │ └─┬ has@1.0.1
│ │ └── function-bind@1.1.0
│ └─┬ is-expression@3.0.0
│ └── acorn@4.0.11
├── pug-linker@2.0.3
├─┬ pug-load@2.0.6
│ └── object-assign@4.1.1
├─┬ pug-parser@2.0.2
│ └── token-stream@0.0.1
├── pug-runtime@2.0.3
└── pug-strip-comments@1.0.2

npm ERR! Darwin 16.5.0
npm ERR! argv "/usr/local/bin/node" "/usr/local/bin/npm" "i" "pug-cli" "-g"
npm ERR! node v6.3.1
npm ERR! npm v3.10.3
npm ERR! path /usr/local/lib/node_modules
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access

npm ERR! Error: EACCES: permission denied, access '/usr/local/lib/node_modules'
npm ERR! at Error (native)
npm ERR! { Error: EACCES: permission denied, access '/usr/local/lib/node_modules'
npm ERR! at Error (native)
npm ERR! errno: -13,
npm ERR! code: 'EACCES',
npm ERR! syscall: 'access',
npm ERR! path: '/usr/local/lib/node_modules' }
npm ERR!
npm ERR! Please try running this command again as root/Administrator.

npm ERR! Please include the following file with any support request:
npm ERR! /Users/kobayashikentaro/npm-debug.log
KobayashiKentaro-no-MacBook-Pro:~ kobayashikentaro$